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Moto Guzzi V700, Ambassador, V7 Special, Eldorado, 850GT - Electrical components

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Alternator conversion

If you are just running stock electrics, you will find the 300 watt loop frame generator to be more than adequate. However, if you start adding lights, heated clothing, etc., you will find that the power supply is not limitless. Loop frame alternator conversions have been around for a long time in various formats. Here are a few examples.

Bob Nolan / Greg Field alternator conversion kit

Greg Field and Bob Nolan put a loop frame alternator conversion kit together and have made it available. I have purchased and installed the kit. It is top notch in every respect and very well done. I am very pleased with how it fits and the power output is fantastic, even at idle. I have nothing but good things to say about this kit. If you are interested in purchasing it, please contact Greg Field directly at greguzzi>at<comcast.net. Here are some words from Greg Field describing the conversion:

Bob Nolan and I are selling a complete kit to replace the 300w generator on your V700, Ambassador, V7 Special, or Eldorado with a 600w Nippon Denso alternator.

The kit includes a new ND 600-watt alternator, a mounting bracket that replaces the generator bracket, and all wiring necessary to make it integrate with the stock wiring. It all bolts right on and requires no changes of any kind to stock parts, not even the generator-belt cover or stock wiring connectors.

The alternator is brand new and covered by an ND warranty. It has an internal regulator. Two wires are necessary to run it: one to the battery and another that connects to switched power. A third wire is optional and goes to the charging light on your dash.

The bracket is welded of 1/4-inch steel. It mounts to the two stock mounting bolts to the engine block. We also added a strap that bolts to the front bolt of the distributor. It will be painted. Bob and I will warranty the bracket as follows: If it cracks or breaks within a year, we'll fix or replace it.

The wiring harness consists of two wires and an adaptor connector. One wire carries the generated electricity to the battery. Another short wire connects to switched power at the coil. The adaptor connector allows attachment of the stock wiring for the generator light on your dash.

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Installation notes

Installation is simple and straightforward. The included instructions are great. Do take the time to install studs to secure the bracket to the block (rather than Guzzi's original bolts).

On my maiden voyage I had trouble with the connector to the idiot light coming loose. The first time I thought perhaps I had failed to connect it. The second time I knew something was up and I gave the female spade connector a little squeeze with my pliers from the toolkit. It still wiggled loose. I solved the problem by replacing the adapter with a simple female spade connector - no more disconnects for 1,000 + miles.

Maynard's alternator conversion

I took these pictures of the alternator conversion Maynard (Neil Hemenway) did on his Eldorado at the MGNOC 2004 National Rally. I hope they prove useful to those interested in such a transformation.

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Batteries

Garden tractor batteries

I used to be a proponent of the very inexpensive lawn and garden tractor batteries such as the Interstate SP30R Battery with 290 CA and 230 CCA or the EverStart U1P-7 garden tractor sized battery with 350 CA and 275 CCA available from Wal-Mart. However, these batteries have low cranking power and vent corrosive gases. I was never completely satisfied with them. But, if you are on a budget, these will definitely get the job done inexpensively.

Drycell batteries

A great battery choice recommended by John Ulrich is the Odyssey PC925MJT with 380 cold cranking amps and 925 cranking amps for 5 seconds. Since it is completely sealed, it is installed on it's side and fits well in the battery tray. Battery Mart and Battery Sales are two online locations with (historically) competitive pricing (thanks to Charlie Mullendore and Howard Blank for the links to the online stores).

George Dockray was kind enough to send me a couple of photos of his PC925 installation. He glued rubber sheet to a piece of 3/4" plywood for the base to get it out of the way of the bolt heads and base tabs.

I installed a PC925L in my Ambassador.

Greg Field reports that the Odyssey PC545 and Odyssey PC680 batteries fit and function well.

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Group 51 batteries

Charlie Mullendore has informed me that the AC Delco 51R-60 battery fits. Here are the details:

  • Cold Cranking Amperage (CCA): 450
  • Cranking Amperage (CA): 530
  • Length: 9.31"
  • Width: 4.94"
  • Height: 8.69"
  • Weight: 28 pounds

Mazda Miata batteries

Charlie Mullendore has informed me that the Marathon MAR-8AM-U1R battery fits (Battery Mart sells them). Here are the details:

  • Cold Cranking Amperage (CCA): 320
  • Cranking Amperage (CA): 400
  • Length: 7 3/4"
  • Width: 5 1/8"
  • Height: 7 1/4"

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Group 55 batteries

The Group 55 battery size is pretty much discontinued by everyone. If you do find one, it may be very old. My recommendation is that you do not waste your time trying to find one of these. However, I've kept the information on them below for reference.

However, based on recommendations from Robert A. Greene and Mark Etheridge of Moto Guzzi Classics, I have now chosen to use an AC Delco Group 55-6 year battery with 535 CCA. I picked one up from my local auto parts distributor. A Napa Group 55 battery may also work, but doesn't fit as well as the AC Delco.

If your local auto parts house just has to have a vehicle to look up a part, try any of the following:

  • 1993 - 1995 Kia Sephia
  • 1987 - 1990 Jeep Wrangler
  • 1978 - 1980 Ford Thunderbird

As for installation, I was able to use the stock battery hold-down bracket and the long L-shaped bolts. I did have to modify the battery a bit, though, in several places. Along the bottom of the battery there is an extra chunk of plastic that is usually used to clamp the battery to the battery tray in cars, etc. This extra chunk got in the way of the four tabs on the battery tray. Some quick work at the bench grinder got rid of those (I just love grinding on a battery with power tools!). Also, on either long side of the top of the battery, I whittled away some extra plastic so that the hold-down bracket would fit snug. I just used a razor blade for this work. Since this is a top post battery, I found some adapters at the local parts store that worked well for mounting my ring connectors.

I am very happy with this battery. The starter cranks much faster and the lights are less susceptible to dimming with engine speed. This upgrade was well worth the extra money and minor modifications.

Follow-up: My AC Delco battery worked very well for nearly 2 years...then died. The battery was already old when I purchased it and no replacements were available. For now, I stuck my old garden tractor battery back in.

Battery hold down bracket for Odyssey PC925

After installing an Odyssey PC925L battery in my Ambassador, I wanted a well fitting hold down bracket. The stock bracket didn't work well and I did not wish to drill any additional holes in my battery tray. So, I decided to craft my own homemade battery hold down bracket. I could have welded a few pieces of steel together and that would have worked just fine. Instead, I decided to use commonly available aluminum pieces and stainless steel fasteners. A hack saw, drill, and file were all the tools needed. There are simpler designs, but this battery hold down bracket can be made by almost any loop frame owner with very basic skills, tools, and readily available materials.

A few notes:

  • The flat stock I used was 1" wide and 3/16" thick.
  • The L-shaped stock I used was 1" x 1" wide and 1/8" thick.
  • I chose to round the exposed corners of the L-shaped aluminum pieces. I traced the corner using a socket of a size I found pleasing. I started by using a hack saw to cut the basic corner shape, then finished it up with a hand file.
  • When everything was complete, I used the wire brush on my bench grinder to clean up the aluminum and give it a brushed appearance.

Disclaimer: I have not tried this bracket with the stock air box. It may extend too far forward and interfere with the stock air box. But, I think the battery could be moved rearward somewhat and provide the needed clearance. The stock battery hold down bracket had a tendency to hit the stock air box, too. I would fit a piece of rubber between the bracket and the air box to prevent damage.

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Odyssey PC925 battery and hold down bracket.Odyssey PC925 battery and hold down bracket.

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Hold down bracket fitted to battery.Hold down bracket fitted to battery.

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View of the underneath of the front fitting portion. T-shaped aluminum stock is not readily available in most hardware stores, so I chose to use 2 L-shaped pieces. Because of this decision, the L-shaped pieces had to extend past the width of the battery to the left and the right. The use of T-shaped aluminum stock would greatly simplify construction and make the overall bracket smaller.View of the underneath of the front fitting portion. T-shaped aluminum stock is not readily available in most hardware stores, so I chose to use 2 L-shaped pieces. Because of this decision, the L-shaped pieces had to extend past the width of the battery to the left and the right. The use of T-shaped aluminum stock would greatly simplify construction and make the overall bracket smaller.

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Close up view of the underneath of the rear fitting portion. The right side flat stock extends further rearward of the angle stock so as to provide a securing location for the right rear L-shaped bolt.Close up view of the underneath of the rear fitting portion. The right side flat stock extends further rearward of the angle stock so as to provide a securing location for the right rear L-shaped bolt.

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Another view of the underneath of the rear fitting portion.Another view of the underneath of the rear fitting portion.

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A view of the rear portion fitted to the battery. The heads of the bolts clear the shape of the battery nicely.A view of the rear portion fitted to the battery. The heads of the bolts clear the shape of the battery nicely.

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View of the left side of the battery installed with the bracket in place.View of the left side of the battery installed with the bracket in place.

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View of the left side L-shaped bolt in the standard position using the standard holes.View of the left side L-shaped bolt in the standard position using the standard holes.

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View of the right side of the battery installed with the bracket in place.View of the right side of the battery installed with the bracket in place.

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View of the right side L-shaped bolt in the reversed position using the standard holes. The L-shaped bolt can easily be installed in this reversed position by inserting it up from the bottom to the left of the drive shaft.View of the right side L-shaped bolt in the reversed position using the standard holes. The L-shaped bolt can easily be installed in this reversed position by inserting it up from the bottom to the left of the drive shaft.

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A close up view of the L-shaped bolt in the reversed position on the right side.A close up view of the L-shaped bolt in the reversed position on the right side.

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The speedometer cable clears the battery bracket just fine.The speedometer cable clears the battery bracket just fine.

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A view of my dusty side cover in place. It clears the bracket just fine.A view of my dusty side cover in place. It clears the bracket just fine.

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A close-up view of the side cover clearing the battery hold down bracket.A close-up view of the side cover clearing the battery hold down bracket.

Battery size/dimensions

Dimensions

Here is the biggest you can go and still use the stock hold down bracket (and fit the side covers):

  • 5 7/16" wide (front to back in the motorcycle)
  • 9 3/8" long (side to side in the motorcycle)
  • 7 1/2" tall (seems that a battery 8.69" tall will fit...I will update this value once I inspect Cam's install at the 2007 Virginia Rally)

Battery group numbers, dimensional specifications, polarity, terminals

Thanks to Charlie Mullendore of Antietam Classic Cycle for providing a link to this information on the Yahoo! Loopframe_Guzzi news group. Information originally from Battery Web.

GroupLengthWidthHeightPolarityTerminals
22F9.5" (240 mm)6.9" (175 mm)8.3" (211 mm)R/H-POS22F0
22NF9.4" (240 mm)5.5" (140 mm)8.9" (227 mm)R/H-POS22NF0
2410.3" (260 mm)6.8" (175 mm)8.9" (225 mm)L/H-POS240
24F10.3" (260 mm)6.8" (175 mm)8.9" (225 mm)R/H-POS24F0
259.1" (230 mm)6.9" (175 mm)8.9" (225 mm)L/H-POS250
268.2" (208 mm)6.9" (175 mm)7.8" (197 mm)L/H-POS260
26R8.2" (208 mm)6.9" (175 mm)7.8" (197 mm)R/H-POS26R0
26 - 708.2" (208 mm)6.9" (175 mm)7.8" (197 mm)C-LINE26 - 700
2712.1" (306 mm)6.8" (175 mm)8.9" (225 mm)L/H-POS270
27F12.1" (306 mm)6.8" (175 mm)8.9" (225 mm)R/H-POS27F0
29NF13" (330 mm)5.5" (140 mm)8.9" (227 mm)R/H-POS29NF0
3313.3" (338 mm)6.8" (173 mm)9.4" (238 mm)R/H-POS330
3410.3" (260 mm)6.8" (175 mm)7.9" (200 mm)L/H-POS340
34R10.3" (260 mm)6.8" (173 mm)7.9" (200 mm)R/H-POS34R0
34 - 7810.3" (260 mm)6.8" (175 mm)7.9" (200 mm)C-LINE34 - 780
359.1" (230 mm)6.9" (175 mm)8.9" (225 mm)R/H-POS350
36R10.4" (263 mm)7.3" (183 mm)8.1" (206 mm)R/H-POS36R0
40R10.9" (278 mm)6.9" (175 mm)6.9" (175 mm)R/H-POS40R0
4111.6" (293 mm)6.9" (175 mm)6.9" (175 mm)R/H-POS410
429.6" (243 mm)6.8" (173 mm)6.8" (173 mm)R/H-POS420
4313.1" (334 mm)6.9" (175 mm)8" (205 mm)R/H-POS430
459.5" (240 mm)5.5" (140 mm)9" (227 mm)L/H-POS450
4610.8" (273 mm)6.8" (173 mm)9" (229 mm)L/H-POS460
479.7" (246 mm)6.9" (175 mm)7.5" (190 mm)R/H-POS470
4812.1" (278 mm)6.9" (175 mm)7.6" (190 mm)R/H-POS480
48/9112.1" (306 mm)6.9" (175 mm)7.6" (192 mm)R/H-POS48/910
4913.9" (353 mm)6.9" (175 mm)7.6" (190 mm)R/H-POS490
49/9315" (381 mm)6.9" (175 mm)7.6" (192 mm)R/H-POS49/930
5013.5" (343 mm)5" (127 mm)10" (254 mm)L/H-POS500
519.4" (238 mm)5.1" (129 mm)8.8" (223 mm)L/H-POS510
51R9.4" (238 mm)5.1" (129 mm)8.8" (223 mm)R/H-POS51R0
527.3" (186 mm)5.8" (147 mm)8.3" (210 mm)L/H-POS520
5313" (330 mm)4.7" (119 mm)8.3" (210 mm)L/H-POS530
547.3" (186 mm)6.1" (154 mm)8.4" (212 mm)R/H-POS540
558.6" (218 mm)6.1" (154 mm)8.4" (212 mm)R/H-POS550
5610" (254 mm)6.1" (154 mm)8.4" (212 mm)R/H-POS560
578.1" (205 mm)7.2" (183 mm)6.9" (177 mm)R/H-POS570
5810.1" (255 mm)7.2" (183 mm)6.9" (175 mm)L/H-POS580
58R10.1" (255 mm)7.2" (183 mm)6.9" (175 mm)R/H-POS58R0
5910.1" (255 mm)7.6" (193 mm)7.8" (196 mm)L/H-POS590
6013.1" (332 mm)6.3" (160 mm)8.9" (225 mm)R/H-POS600
617.6" (192 mm)6.4" (162 mm)8.9" (225 mm)R/H-POS610
628.9" (225 mm)6.4" (162 mm)8.9" (225 mm)R/H-POS620
6310.2" (258 mm)6.4" (162 mm)8.9" (225 mm)R/H-POS630
6411.7" (296 mm)6.4" (162 mm)8.9" (225 mm)R/H-POS640
6512.1" (306 mm)7.5" (190 mm)7.6" (192 mm)L/H-POS650
6612.1" (306 mm)7.6" (192 mm)7.6" (194 mm)L/H-POS660
708.2" (208 mm)7.1" (179 mm)7.3" (196 mm)L/H-POS700
718.2" (208 mm)7.1" (179 mm)8.5" (216 mm)L/H-POS710
729.1" (230 mm)7.1" (179 mm)8.3" (210 mm)L/H-POS720
739.1" (230 mm)7.1" (179 mm)8.5" (216 mm)L/H-POS730
7410.3" (260 mm)7.3" (184 mm)8.8" (222 mm)L/H-POS740
759.1" (230 mm)7.1" (179 mm)7.3" (186 mm)L/H-POS750
7613.1" (334 mm)7.1" (179 mm)8.5" (216 mm)L/H-POS760
7810.3" (260 mm)7.1" (179 mm)7.3" (186 mm)L/H-POS780
7912.1" (307 mm)7.1" (179 mm)7.4" (188 mm)L/H-POS790
859.1" (230 mm)6.8" (173 mm)8" (203 mm)R/H-POS850
869.1" (230 mm)6.8" (173 mm)8" (203 mm)L/H-POS860
909.5" (242 mm)6.9" (175 mm)6.9" (175 mm)R/H-POS900
9111" (278 mm)6.9" (175 mm)6.9" (175 mm)R/H-POS910
9212.5" (315 mm)6.9" (175 mm)6.9" (175 mm)R/H-POS920
9313.9" (93 mm)6.9" (353 mm)6.9" (175 mm)R/H-POS930
94R12.4" (315 mm)6.9" (175 mm)7.5" (190 mm)R/H-POS94R0
95R15.6" (394 mm)6.9" (175 mm)7.5" (190 mm)R/H-POS95R0
96R9.6" (242 mm)6.2" (173 mm)6.9" (175 mm)R/H-POS96R0
97R9.9" (252 mm)6.9" (175 mm)7.5" (190 mm)R/H-POS97R0
98R11.2" (283 mm)6.9" (175 mm)7.5" (190 mm)R/H-POS98R0
998.2" (207 mm)6.9" (175 mm)6.9" (175 mm)L/H-POS990
10010.3" (260 mm)7" (179 mm)7.3" (188 mm)L/H-POS1000
10110.3" (260 mm)7" (179 mm)6.7" (170 mm)L/H-POS1010

Bullet terminal connections

Thanks to Charlie Mullendore of Antietam Classic Cycle for providing this information on the Yahoo! Loopframe_Guzzi news group.

Bullet terminals are available in two common sizes: 0.157" and 0.176". The electrical connections on the loop frames use the 0.157" sized bullet terminals.

Coil alternatives

I extracted some of this information from the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!). The epoxy-filled "Bosch Blue" is the most frequently cited alternative coil used (some report bad experiences with oil filled coils). Whichever one you choose, be sure that it has 3 Ohm resistance. A great cross-reference is any Volkswagen Beetle manufactured between 1975 and 1979 (12 volt).

Coil information

Thanks to Ralf Brinkmann for sending me this information. Ralf is remembering much of this from an extract of a schoolbook. In Ralf's own words:

Some years ago with my Guzzi I changed to the blue Bosch coil - so last year I gave away all my black Bosch coils to the owner of a BMW-Isetta. I collected these coils over the years when I had air-cooled Volkswaggons - so I'm not able to measure but they all differ a little bit in size and resistance.

But I have a chart for you. The chart compares the black (E), the blue (K), and the red (KW) Bosch coil and shows how fast a modern transistor driven coil loads. In this chart the Guzzi engine would count as 3-Cyl. due to the asymetric arrangement.

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The lower the the resistance of the coil the faster the coil loads up to a definite voltage line - important at high engine speed.

The limit for the breaker points is the 5A line. For this reason the red E-coil needs a fat 1.8 Ohm resistor in series connection. The resistor may be shortened by a relays while starting.

If you want more amps you must use electronic components. Modern Guzzi coils - e.g. Jackal - have less than 1.0 Ohm resistance in the primary circuit.

In combination with the breaker points the powerful 4th coil will need something like this: Steuergeraete fuer Zuendanlagen mit Unterbrecherkontakt und Fliehkraftverstellung

These breaker point driven TSZ-U (or TSZ-K) controllers do not close the primary coil circuit for a fixed angle but for a fixed max. time - maybe 4 ms - depending on the coil - in German called "automatische Schliesswinkelregelung"

I wonder if the tiny Guzzi distributor cap would survive the high voltage - maybe one day I'll ask the FIAT-500 club.

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Coil terminal connections

Some loop frame coils do not have the positive and negative terminals identified with easy-to-understand symbols (such as '+' for positive and '-' for negative). Instead, the coil terminals are labeled with numbers. The terminal labeled with the number one ('1') is the negative terminal. The terminal labeled with the number fifteen ('15') is the positive terminal.

If it is not possible to read these numbers, you may want to count the male spade connector leads at each terminal. Usually, the positive terminal has two leads while the negative terminal has one lead.

Electricity usage by component

Loop frame generators are rated at 300 watts at 2400 RPM. Since this is a 12 volt system, this equates to 25 amperes (300 watts / 12 volts = 25 amperes). Or, since the charging system is usually charging at about 14 volts, the equation becomes: 300 watts / 14 volts = 21.4 amperes. In either case, we're still dealing with about 300 watts of power. Where does all this juice go?

Electrical component Watts used with the stock civilian specification Watts used with the stock police specification Watts used with my Ambassador
Coil
4 amps max, usually 2 amps
56 watts max, usually 28 watts
28 28 28
Headlight low beam 40 40 55
Headlight high beam 45 45 60
Tail light 5 5 5
Dash illumination bulb 3 3 3
Headlight indicator bulb 3 3 3
Right rear blue light - 5 -
Left rear blue light - 5 -
Right front red light - 15 -
Left front red light - 15 -
Supplementary light (spot light?) - 15 -
Left driving light - - 55
Right driving light - - 55
Right front running light - - 23
Right rear running light - - 23
Left front running light - - 23
Left rear running light - - 23
Horn, brake light, starter, turn signals, most dash indicator bulbs, etc. I will ignore these components as usage is temporal in nature.
Total running low beam 79 134 296
Total running high beam 84 139 301

These calculations are rough and do not take all factors or electrical components into consideration (such as resistance), so these numbers are probably a little low. They are helpful, though, even given the limitations.

Two things are immediately apparent from these numbers. First, the stock system is set up with plenty of reserve, even with the police lights (although I don't know wattage usage for components such as the radio, etc.). Second, adding high wattage bulbs quickly puts my Ambassador at the limit. When the generator cannot produce enough electricity to keep up with demand, the power will be scavenged from the battery. After a while, the battery's power will be depleted and things start getting very ugly. Initially, the lights will dim. But if the situation persists, there will not even be enough power to operate the coil, and so the ignition will start cutting out.

Electronic ignition - alternatives

I've not tried any of these alternative electronic ignitions.

Electronic ignition - Harper's Pertronix unit

The purchase

Apr 04, 2004 - I purchased the Harper's High Output Electronic Ignition kit today (it's being shipped). I will post my experiences with this system here from installation to performance. Since I wasn't able to find any information on the web about other user's experiences before I spent my USD $330.00, I'll let you know if I think I spent my money wisely.

Background

Harper's electronic ignition kit is brand new in the last 6 months (Fall, 2003) and is specifically designed for the V7 / V700, 750 Ambassador and 850 Eldorado loop frames. The installation promises to be quick and easy, as no modifications to the motorcycle are needed. To my knowledge, this is the only electronic ignition kit ever made for loop frames (and about 30 years tardy, too).

Alternatives

I do know of at least one person who adapted a Dyna III electronic ignition system and distributor from a Tonti frame bike to an Ambassador. This required a little creative grinding to the generator to allow sufficient room for the distributor assembly to rotate while setting the timing. He was happy with this set up and used it until the Dyna III went bad. Anticipating the eventual demise of the Dyna III, he was carrying a spare distributor with the points already set. A few minutes later, he was back on the road. I certainly plan to carry a spare set of points and condenser, for just such an occurrence - especially with an electronic ignition system that is as new as this one is.

The kit

Apr 08, 2004 - The kit arrives and is opened with eager anticipation. Contents fall into two classes: boring and exciting.

The boring contents are those items that I already have, are in good shape, and that I don't need to replace: 1 rotor, 1 distributor cap, 2 spark plug caps, 1 spark plug wire set, and 3 ignition wire boots. My perception is that these are just filler items intended to make the kit appear larger, more comprehensive, more impressive, and worth USD $330.00. That being said, it is nice to start off with brand new stuff all around.

The exciting items include the coil and the electronic ignition igniter. Both of these components are made by a company called Pertronix. Pertronix does NOT sell directly to the public. Additionally, Harper's Moto Guzzi has an exclusive agreement with Pertronix regarding the electronic ignition igniter. So, while you may be able to find the coil from another Pertronix dealer, and you can certainly find the boring pieces from any one of a number of sources, you won't be able to get a hold of the electronic ignition igniter - which is the brains of the system and is precisely what you need.

The coil is their "Flame-Thrower" model, part number 40611 (black in color, epoxy filled, 3.0 Ohm, designed for 12 volt electrical systems, 40,000 available volts, draws a maximum of 4 amperes, but typically draws 2 amperes). If the coil goes bad outside of the 90 day warranty, a replacement can be had from a Pertronix dealer for around USD $50.00.

The electronic ignition igniter is their "Ignitor" model, part number MR-121 (RPM range: 0 - 15,000; Coil resistance: 1.5 ohms or more). The igniter is a two-piece setup. One part is a plate that replaces the standard points plate. This piece has two wires that connect to the coil. The other part is a magnetic rotor that fits over the cam on the distributor shaft. Both of these pieces are labeled with the model number (MR-121).

Warranty

Harper offers this warranty: "Harper Accessories warranties the Harper's Ignition against defects in materials and workmanship for a period of 90 days from date of purchase (must have invoice for return). Improper installation or any alteration of the product renders all warranties null and void. Warranty is limited to the replacement or repair of the product only, which is at the discretion of Harper Accessories."

However, the manufacturer of the coil (Pertronix) offers a 90 day warranty on the coil and a 30 month warranty on the electronic ignition igniter.

I am happy to see that the manufacturer is willing to stand behind the electronic ignition igniter for 30 months. I see that as the component most likely to fail, anyway. Too bad Harper Accessories isn't willing to do so. If I have trouble outside 90 days, I guess I'll try to deal directly with the manufacturer. Although since Harper's has an exclusive agreement with them, I'm doubtful that I'd get a replacement.

Installation instructions (taken directly from the installation sheet provided by Harper)

Steps:

  1. Installation is very simple and straight forward. It is simply the removal and reinstallation of ignition parts that are normally changed during a tune-up.
  2. Remove the fuel tank from the bike and remove the old ignition coil, distributor cap, rotor, spark plug and coil wires, and points plate.
  3. Replace the old coil with the high output coil from the kit using the existing coil bracket. Note: Do not use any other coil with this igniter unit.
  4. Install the igniter plate in place of the old points plate being careful to reconnect the coil power wire 12 volt positive (+) to the positive (+) side of the coil along with the red wire from the igniter. Connect the black wire to the negative (-) terminal on the coil.
  5. Note: If your bike has a tachometer, the tach wire should be connected to the black (negative) (-) terminal on the coil.
  6. The magnetic rotor is shaped internally to fit over the points cam. It is a slip fit over the cam and will press on easily if aligned properly.
  7. Install the new distributor rotor and distributor cap with the new spark plug and coil wires.
  8. Check the ignition timing with a strobe light by revving the motor until the distributor is fully advanced and adjust the timing by turning the distributor until the full advance mark on the pulley is aligned with the arrow on the engine.

Additional installation instructions

Although my assumption was that the condenser is no longer needed, the above instructions don't make any mention of it. A quick call to Harper's and my thoughts were confirmed. Plus, I got another tidbit.

It is possible for loop frames to run with the distributor reversed 180° - using the standard points and condenser. However, loop frames won't run that way with the new electronic ignition. One way to quickly check if your distributor is properly inserted is to bring the left hand cylinder (number 2 cylinder) to top dead center on the compression stroke (free-play on both valves). At this point, you should be able to look at the distributor and determine which cam lobe the points are on: the wide lobe or the narrow lobe. If you are on the narrow lobe, then you are exactly where you need to be. If you are on the wide lobe, then you need remove the distributor, rotate the shaft that runs through the distributor 180°, and reinsert the distributor. Be sure to make careful observations (and maybe even a drawing) before removing the distributor so that you know exactly where the distributor needs to be located.

Installation

Apr 10, 2004 - Saturday morning arrives with temperatures between 25° and 30° Fahrenheit; a lovely Minnesota Spring day! Out to the garage and I commence installation following the instructions provided above. It really is an easy installation. The only aspect of the setup that was only mildly disappointing is that the leads on the coil are fastened with standard sized nuts, rather than metric. A 10 mm wrench comes close, but a 3/8" wrench is what's needed. That aside, the kit fit perfectly.

The engine started after a few cranks, but was running rough. I expected this as I knew I would need to adjust the timing. So I revved the engine, shot my timing gun at the pulley, and dialed the distributor in. This procedure requires the use of three hands unless you tighten the spring loaded adjusting screw on the underside of the twist grip throttle while the engine is revved, which is what I did. Now the engine was running great!

The test ride

Apr 10, 2004 - On go the gloves and helmet and I rode across the street to the grade school parking lot for a short warm-up ride. Everything seemed great, even the snow flurries! So off I headed for little faster test ride on city streets (top speed around 45 - 50 MPH). The engine revved well, idled nice, and cruised like it should. I was a little cold at this point, so I headed back home. The highway test will have to wait for warmer weather.

Apr 11, 2004 - Warmer weather has arrived! I took the Ambassador out for an 80 mile run. 40 miles were two-lane (twisties, straights, small towns; 35 - 70 MPH) and 40 miles were straight highway (70 - 80 MPH the whole way). The timing and ignition worked very well...the Ambassador just felt great. I didn't check the fuel mileage, but I will next time.

Apr 14, 2004 - I took the Ambassador out for a 100 mile spin through the Minnesota River Valley. Some twisties, some straights, several quaint Minnesota towns, beautiful scenery - especially at sunset, a very enjoyable ride. Timing and ignition were flawless and I was very happy with the performance at highway speeds (60 - 80 MPH), as well as throughout the rest of the range. The bike just seems to respond better to the throttle with the electronic ignition. My fuel mileage was 38.2 M.P.G.

Apr 30, 2004 - I took the Ambassador up to Duluth, MN to purchase my Aerostich suit. It's about 187 miles each way on Interstate 35. I ran the bike about 70 the whole way there and back...never missed a lick! My fuel mileage was 38.2 M.P.G.

Apr 27, 2005 - It's been a year now and I've ridden the Ambassador quite a bit. I've never had a lick of trouble with the electronic ignition. I'm quite pleased with this upgrade.

Nov 07, 2005 - In early October - while I had my transmission out to repair the leaking camshaft plug - I failed to properly insulate the wires going to the ignitor module upon reassembly. The wires shorted and fried the ignitor less than a mile from my house. Ug. So, I gave Pertronix a call. After diagnosing the problem, we discovered that the ignitor was indeed destroyed. Sending them my ignitor and a copy of my original receipt, Pertronix sent me a new ignitor. Great company. Great service. Great warranty coverage. Enough said.

Sep 03, 2006 - I was heading out for a ride but got no further than the front entrance to my subdivision. Bike died suddenly. I checked the petcocks and found that I had forgotten to turn them on. I turned them on, but the bike absolutely would not start. I thought maybe I had flooded it. No matter, I pushed the bike back to my house...hot, humid, sweaty, disgusted. Pulled both plugs to check for spark. None. Tested the coil, it is fine. Performed the battery of Pertronix tests from the last time I had been through this. The Pertronix unit failed every test. Out with the Pertronix unit, in with the tried and true points and condenser system. Crank the engine over and it roared to life. This time, I'm absolutely certain that nothing was grounding out on anything else...and I'm beginning to wonder about last time, too.

My initial conclusion

I'll be the first one to admit that I dislike points and condenser systems. Not just on Moto Guzzis, but on any machine. Yes, they work; but they've always taken more of my time and given me more headaches than I care to put up with. Given what I've said here, I may be a little biased in my opinion - so take that into consideration.

I'm glad I purchased this electronic ignition kit. My Ambassador runs better now than it ever has before. As long as the electronic ignition doesn't go out on me, I think I'll remain happy.

Now, if you are happy with your current system and don't want to change to electronic ignition, then don't. I think you are well justified in choosing to stay with a tried and true technology. It sure is easier to repair or replace points and condenser systems in the middle of nowhere on your around-the-world tour.

But, if you are of like mind when it comes to points and condenser systems, and are tired of fiddling around under your distributor cap, I recommend that you purchase this kit.

My conclusion after a year and a half of use

While I was waiting on my replacement ignitor module from Pertronix, I put the standard points and condenser back in and road it that way for a while. Performance seemed identical (contrary to my initial - perhaps optimistic - impression). On future projects, I highly doubt I will purchase another electronic ignition kit. Instead, I'll use the cheap, tried-and-true points and condenser set up.

Final analysis

With two failures of the Pertronix unit, I'm definitely sticking with points and a condenser.

Pertronix documents

The following documents are applicable to installing and troubleshooting the Pertronix ignitor. USE AT YOUR OWN RISK!!!

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NOTE: If you have trouble viewing PDF files inside your browser, try saving them to your computer (right-click the link, then choose the save option). Then, open each file directly in Adobe Acrobat Reader.

Fuse block

Here is a photo I put together recently of the front and back of the original fuse block.

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Back and front view of the original fuse block.Back and front view of the original fuse block.

Fuse block alternatives

Some loop frame owners like to relocate the standard fuse blocks to alternative locations. Reasons for this include (1) reducing wire clutter at the headlight, (2) making the fuses more easily accessible, and (3) tinkering is just plain fun.

Stephen Brenton's side cover fuse block (in his own words)

I remade the battery tray using 316SS. Then decided to attach an after market fuse panel to an upright leg, which also serves as a battery hold down. All this hides behind the (easily accessible) left side cover.

So far I've only got 3 leads from the fuse block, purple is horn, blue is headlights, red is ignition. (I made my wiring harness so I could do exactly what I wanted.)

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Stephen Brenton's fuse block and battery hold downStephen Brenton's fuse block and battery hold down

Bill Dudley's replacement fuse block

A replacement for the stock loopframe fuse block. Improvements over the old stock fuse block:

  1. Uses modern mini-blade fuses.
  2. Fuses are labeled as to circuit and size.
  3. Fuse connections are not worn out and still have spring tension.
  4. Includes wiring for headlight relays to keep headlight switch from melting.
  5. Designed to leave lots of room for deeper lamp assembly, like high powered H4 or even a HID light.

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Front view of Bill Dudley's fuse panelFront view of Bill Dudley's fuse panel

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Rear view of Bill Dudley's fuse panelRear view of Bill Dudley's fuse panel

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Wiring diagram for Bill Dudley's fuse panelWiring diagram for Bill Dudley's fuse panel

Phoenix Police Department fuse block relocation

Tom Short sent me these photos of how the Phoenix Police Department relocated the fuse block.

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Front viewFront view

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Rear viewRear view

Replacement fuse block that accepts ATO/ATC blade style fuses

In addition to the fuse panel replacements suggested by others, I found one that bolts perfectly in the stock location inside the headlight and takes the ATO/ATC blade style fuses. I purchased it from Waytek Wire. Search for item number 46081. I've yet to use it as my original is holding up very well. I think the knob securing the clear plastic cover will interfere with the headlight, but other than that I think it would be perfect.


Waytek Wire item number 46081

Generator bearing cross-references (Bosch)

Large Bearing (MG# 12700226) located at the front of the generator (pulley side)

  • 17 mm ID x 40 mm OD x 12 mm thick
  • Bearing numbers for single sided shielded bearings (as original)
    • FAF 203KD
    • FAG 6203 Z
    • FED 1203F
    • MRC 203-SF
    • ND 7503
    • New Departure 7503
    • NH 203P
    • RIV 01 APL
    • SKF 6203 Z
    • STEYR 6203 Z
  • Bearing numbers for two-sided sealed bearings (completely fine to use and I consider an upgrade to the orginal)
    • FAF 203PP
    • FAG 6203.2RS
    • FED 1203RR
    • MRC 203-SZZ
    • ND Z99503
    • New Departure Z99503
    • NH 203KK
    • RIV ALN 17
    • SKF 6203-2RS
    • STEYR 6203.2RS

Small Bearing (MG# 12700217) located at the rear of the generator (non-pulley side)

  • 15 mm ID x 35 mm OD x 11 mm thick
  • Bearing numbers for single sided shielded bearings (as original)
    • FAF 202KD
    • FAG 6202 Z
    • FED 1202F
    • MRC 202-SF
    • ND 7502
    • New Departure 7502
    • NH 202P
    • RIV 02 APL
    • SKF 6202 Z
    • STEYR 6202 Z
  • Bearing numbers for two-sided sealed bearings (completely fine to use and I consider an upgrade to the orginal)
    • FAF 202NPP
    • FAG 6202.2RS
    • FED 1202RR
    • MRC 202-SZZ
    • ND Z99502
    • New Departure Z99502
    • NH 202KK
    • RIV ALN 15
    • SKF 6202-2RS
    • STEYR 6202.2RS

Generator bearing cross-references (Magneti Marelli)

Large Bearing (MG# 95181209) located at the front of the generator (pulley side)

  • 15 mm ID x 35 mm OD x 11 mm thick
  • Bearing numbers for open bearings (as original - reuse original metal shields)
    • FAF 202K
    • FAG 6202
    • FED 1202
    • MRC 202-S
    • ND 3202
    • New Departure 3202
    • NH 202
    • RIV 02 A (original manufacturer and code of bearing)
    • SKF 6202
    • STEYR 6202
  • Bearing numbers for two-sided sealed bearings (completely fine to use and I consider an upgrade to the orginal)
    • FAF 202NPP
    • FAG 6202.2RS
    • FED 1202RR
    • MRC 202-SZZ
    • ND Z99502
    • New Departure Z99502
    • NH 202KK
    • RIV ALN 15
    • SKF 6202-2RS
    • STEYR 6202.2RS

Small Bearing (MG# 95181219) located at the rear of the generator (non-pulley side)

  • 12 mm ID x 32 mm OD x 10 mm thick
  • Bearing numbers for open bearings (as original - reuse original metal shields)
    • FAF 201K
    • FAG 6201
    • FED 1201
    • MRC 201-S
    • ND 3201
    • NH 201
    • RIV 03 A (original manufacturer and code of bearing)
    • SKF 6201
    • STEYR 6201
  • Bearing numbers for two-sided sealed bearings (completely fine to use and I consider an upgrade to the orginal)
    • FAF 201NPP
    • FAG 6201.2RS
    • FED 1201RR
    • MRC 201-SZZ
    • ND Z99501
    • New Departure Z99501
    • NH 201NN
    • RIV ALN 12
    • SKF 6201-2RS
    • STEYR 6201.2RS

Generator belt cross-references

Thanks to Mark Etheridge of Moto Guzzi Classics and Bob Greene for providing key starting information for these cross-references.

Magneti Marelli generator (MG# 12702500)

The original belt was a Pirelli 60404/A.

  • Europe: Goodyear 10AV0775
  • Dayco 15300 (metric part number 11A0760). 30.60" outside circumference, 30.00" effective length, 0.44" wide, 36°
  • Dayco 15305 (metric part number 11A0775). 31.10" outside circumference, 30.50" effective length, 0.44" wide, 36°
  • Dayco 15310 (metric part number 11A0785). 31.60" outside circumference, 31.00" effective length, 0.44" wide, 36°
  • Gates 7300. 777 mm (30.58") outside circumference, 762 mm (30") effective length, 10 mm (0.41") wide, 36°

    Ken Wisdom had the following experience with the Gates 7300 belt:

    I tried the 7300 model belts on my Magneti Marelli generator equipped bike and I had to use about 6 shims on the inside and it was still pretty tight. I then tried a 7312 belt (same width, slightly longer) and it seems to fit very well. 2 shims inside 2 outside. I do have the genny mounted correctly with the stud in the hole on top of the engine. Thought this might help.

  • Gates 7305. 792 mm (31.18") outside circumference, 777 mm (30.6") effective length, 10 mm (0.41") wide, 36°
  • Gates 7312. 802 mm (31.58") outside circumference, 787 mm (31") effective length, 10 mm (0.41") wide, 36°
  • Goodyear 15305. 30.000" effective length, 0.44" wide
  • Goodyear 15321. 31.500" effective length, 0.44" wide

Bosch generator (MG# 12702505)

The original belt was 10 mm wide, 8 mm deep, and 754 mm long and was made by Pirelli.

Note: These belts should also work for any bike that has a Bob Nolan/Greg Field alternator conversion.

  • Europe: Goodyear 10AV0750
  • Europe: Gates 6210MC
  • Dayco 15290 (metric part number 11A0735). 29.60" outside circumference, 29.00" effective length, 0.44" wide, 36°
  • Dayco 15295 (metric part number 11A0750). 30.10" outside circumference, 29.50" effective length, 0.44" wide, 36°
  • Gates 7290. 751 mm (29.58") outside circumference, 737 mm (29") effective length, 10 mm (0.41") wide, 36°
  • Gates 7292. 758 mm (29.83") outside circumference, 743 mm (29.25") effective length, 10 mm (0.41") wide, 36°

    I've used the Gates 7292 belt on a Bosch equiped Ambassador and Eldorado with no problems. If I had to recommend a single belt that I am most confident will fit Bosch equiped models, the Gates 7292 would be it.

  • Gates 7295. 764 mm (30.08") outside circumference, 749 mm (29.5") effective length, 10 mm (0.41") wide, 36°
  • Goodyear 15295. 29.000" effective length, 0.44" wide
  • Goodyear 15301. 29.500" effective length, 0.44" wide

Generator bracket

There are a number of way that every generator bracket should be improved BEFORE bad things happen (and bad things will eventually happen if improvements are not made). I've labeled each of the following with a "required" or "recommended" rating that reflects my personal belief about each modication.

Generator belt

Required. Don't over tighten the generator belt. It is far better for the belt to be too loose rather than too tight. Running the belt too tight will put a lot of pressure on the generator bracket and can crack the bracket or pull the bracket securing bolts out of the block.

Generator bracket securing bolts

Required. The two bolts that secure the generator bracket to the engine block should be changed to studs. McMaster-Carr item number 98867A310 is what I recommend (30 mm x 8 mm x 1.25 mm). Screw the long end into the block with red loctite.

Generator locating pin

Required. There is a locating pin at the front of the generator that fits into a corresponding hole in the engine block. Make certain that the locating pin is well secured into the body of the generator. The use of blue loctite is a good idea. Also, ensure that when the generator is mounted in the bracket, that the body of the generator comes into contact with the curve in the engine block. This curve serves to support the front of the bracket and there should be firm contact between the bottom of the generator and top of the engine block.

Generator bracket

Recommended. Weld an additional brace to the bracket that extends to the front-most distributor securing bolt. This one modification adds to the strength and stabiliy of the generator bracket. It also greatly reduces the stress on the two generator bracket securing bolts (which should be changed to studs).

Generator brush cross-references

I extracted this recommendation from Ralf Brinkmann off of the Yahoo! Loopframe_Guzzi news group.

Bosch Generator

  • Volkswagen part number 111 903 515 E (for 6 volt generators)
    The dimensions of each brush are 6 mm thick x 22 mm wide x 25 mm long
    Fits: Beetle 1946-1966; Ghia 1956-1966; Type 3 1962-1966; Bus 1952-1966

Magneti Marelli Generator

Unknown.

Generator field coil insulating wrap

I use 3M Glass Cloth Electrical Tape 27 in a 1/2" width. If you are going to all the trouble to rebuild an old generator, you might as well re-wrap the field coils. It isn't difficult, but does require a bit of patience and a light touch.

Generator field coil screws - Magneti Marelli

If you can't get the original screws out without destroying them, McMaster-Carr has got you covered. Search for item number 92010A630 (18-8 stainless steel flat head phillips machine screw; 10 mm x 1.5 mm x 20 mm).

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Generator repair - Magneti Marelli

I had the opportunity to rebuild the Magneti Marelli generator on a V700 project bike for a customer. Here is the disassembly process.

  1. Here it is...the mightly lump of a Magneti Marelli generator...as fitted to the V700 and most Ambassador models.

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  2. Remove the nut that secures the pulley in place. I used an pnuematic impact wrench and it came off very easily.

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  3. Remove the pulley from the shaft. You may need to use a gear puller.

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  4. Withdraw the spacer and the Woodruff key.

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  5. Remove the two nuts that secure the rear end cap in place.

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  6. Withdraw the bolts from the front.

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  7. Remove the front plate.

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  8. Remove the housing from the front.

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  9. Replace the washer and nut on the shaft and support the shaft in a vice as shown. Note: I am not clamping the shaft in the vice, but rather supporting the shaft.

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  10. Drive the rear housing off the shaft. The one I rebuilt came off easily. Note the small collection of dried spiders!

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  11. A view of the rear cap. Notice the wavy spring washer. It was originally positioned behind the bearing, at the rear most point of the rear cover, but migrated forward as I drove the rear cap off.

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  12. Now it is time to remove the rear bearing from the shaft.

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  13. Support the bearing as shown, then drive the shaft out with a drift.

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  14. Then remove the washer.

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  15. Now turn your attention to the inside of the front plate. Note the wire spring. Remove it with a small screwdriver then withdraw the metal shield.

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  16. Drive out the bearing as shown. Note the presence of the metal shield and wavy spring washer on the other side of the bearing, too.

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  17. A couple photos of the front bearing assembly.

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  18. Remove the wires protruding through the main body.

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  19. Remove the screws that secure the field coils to the main body. This can be, by far, the most difficult part of disassembly.
    • Start by giving the head of screw a good solid smack with a hammer, supporting the inside of course. Then soak the screws with your favorite penetrating oil for at least 24 hours. Heat can also be used, but you'll want to be careful about burning insulation and the coil wrap (if you aren't re-wrapping...I always rewrap).
    • I've had mixed luck using a large phillips bit from a hand impact screwdriver. The one I have fits nicely in my 1/2" breaker bar. Then I support the main body of the generatory in my drill press vice. With the breaker bar in place, I bear down on top of the breaker bar with the drill press, then rotate the breaker bar. Sometimes it works and the screw pops loose. Sometimes the slots in the screw simply shear off. The good news is that universal replacements of the screws used on these generators are readily available. So, if one does foul on you, drill it out and replace it with a new one.

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  20. Remove the field coils carefully.

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  21. Remove the positioning pin.

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Ignition coil operation test

Thanks to Joe Jump who posted this information on the Yahoo! Loopframe_Guzzi news group in reply to a post from Jon (lennonjas). In Joe's own words:

Since it is so uncommon for an ignition coil to go bad, I'd recommend one last check to absolutely verify you have a bad coil. I'd recommend you isolate it down to ONLY the coil being tested. You could do this by...

  1. Disconnecting the low tension wires of the bike's harness from your coil - the switched hot lead from the ignition switch, the neg lead that goes to the dist, and the lead to the tach (if so equipped), and anything else that might be hooked up to the coil.
  2. Remove the high tension lead running from the from coil to dist and replace with one of the spark plug wires with a known functioning plug (lawnmower, good used plug, etc.). Lay the spark plug on the engine case somewhere so it gets a good ground.
  3. Connect one end of a scrap piece of primary wire (aprox. 16 gage, most anything will do) to the negative side of the coil. Strip the other end & twist the strands - you will be momentarily touching this end of the wire to a chassis ground. A test lead equipped with a couple alligator clips would be ideal.
  4. Connect another test lead from the battery pos post to the positive side of the coil. Once again, a test lead with alligator clips would be great.
  5. Momentarily touch the negative test lead to ground, then remove from the ground while watching the spark plug, looking for a spark. The coil should spark once every time the lead is lifted off the ground.

This set-up should eliminate all other variables & isolate your troubleshooting down to the coil. You won't be distracted by cranking the engine over or worrying about getting zapped - you can concentrate on watching the plug looking for a spark. If this test results in a spark at the plug, your problem is not in the coil. At that point I probably would reconnect the pos lead from the harness to the coil & try again. If good, add more components one at a time until you isolate where the problem is.

Labels for fuse panel and distribution block

A big thanks to Charles Hamer for digitizing the labels for the fuse block and distribution panel. There are 2 pages in this PDF file. The first page shows the original labels. The second page shows a cleaned up version of the labels.

Note on printing this PDF file: When printing this PDF file, be absolutely sure that "Page scaling" is set to "None". If you don't do this, your print will not be of the proper size.

To view PDF files, you will need to download and install the free Adobe Acrobat Reader version 5.0 or higher.

NOTE: If you have trouble viewing PDF files inside your browser, try saving them to your computer (right-click the link, then choose the save option). Then, open each file directly in Adobe Acrobat Reader.

Rubber boot for the oil pressure sending unit

Thanks to Charles Hamer for sending me this information in a private communication:

For the little rubber boot to cover the oil pressure sending unit (MG# 12717600), Napa has one that fits like a glove.

Napa part number 727302.


Napa part number 727302; rubber boot for oil pressure sending unit

Rubber boot for the starter button

Thanks to Charles Hamer for sending me this information in a private communication:

For the little rubber boot to cover the 2 terminals for the starter button (MG# 25707100), Napa has an awesome one used for distributors, and it fits our starter buttons terminals like a glove.

Napa part number 727300.


Napa part number 727300; rubber boot for starter button

Solenoid cross-reference (for Bosch starters)

The original Bosch part number is 0-331-302-022 or 0 331 302 022 or 0331302022. Here are several generic cross-references for this solenoid. I haven't tried all of these myself, but I understand they work just fine.

  • Universal replacment from Holcombe Armature Company: Bosch BH, 12 Volt, 3-Terminal, item number 06-S808
    Bosch solenoid with specifcations: 12 Volt, 3-Terminal, Battery Terminal M8 x 1.25, Motor Terminal M8 x 1.25, Switch Terminal Male Spade, 11mm Hole in Plunger. Replaces BOSCH 0-331-302-031, 0-331-302-040, 0-331-302-057, 0-331-302-064, 0-331-302-073. Reference 6620-2821, 66-9125. Used in Lester 16300, 16443, 16450, 16530, 16532, 16546.
    Thanks to Jim Chamberlin for sending me information about this solenoid in a personal communication.
  • Advance Auto Parts: Standard SS221
  • Advance Auto Parts: Borg Warner S523
  • Advance Auto Parts: Niehoff SD29961
  • Advance Auto Parts: GP Sorenson 285011
  • Napa Auto Parts: Echlin ST222

The solenoid is used on the following vehicles (with manual transmissions...I believe the automatic transmission uses a different part):

  • 1968 - 1973 Volkswagen Fastback
  • 1968 - 1973 Volkswagen Squareback
  • 1969 - 1974 Volkswagen Karmann Ghia
  • 1969 - 1979 Volkswagen Beetle
  • 1971 - 1972 Volkswagen 411
  • 1973 - 1974 Volkswagen 412
  • 1974 - 1979 Volkswagen Transporter
  • 1975 - 1979 Volkswagen Campmobile
  • 1981 Volkswagen Vanagon
  • 1970 - 1976 Porsche 914

Solenoid mounting

Thanks to Paul Linn for providing this information on the Yahoo! Loopframe_Guzzi news group. In Paul's own words:

If you put the solenoid on upside down then the wrong terminal will get hooked to the positive and it will get very hot when you turn the key on. Ask me how I found this out! The part number etc on the solenoid should be visible when looking at it from above and the starter relay terminal will be on the outside when it's mounted on the bike.

Starter, Solenoid, and Starter Relay

Troubleshooting

Sometimes pushing the start button results in clicks, and the starter does not turn the engine. There are a number of things you can try when this occurs:

  1. First off, give the solenoid a good rap with a rubber mallet. It may be that things are just a little bound up and the rap may be all that's needed. Growing up, we had a lawn mower that required this treatment...it worked for years!
  2. Check all of your connections to be sure that they are making good contact.
  3. Since a clicking sound is heard, the starter button is most likely fine. The starter wouldn't be making any sounds if the button weren't making the connection.
  4. It may be that the battery is discharged and not supplying sufficient power. If you have a charger, you can charge it and see if that makes a difference. Alternatively, you could use jumper cables from a running automobile to provide sufficient juice.
  5. If the starter still clicks when you know you have sufficient battery power, then it's time to determine whether or not the starter is bad by bypassing the starter relay and the solenoid with a pliers or a screwdriver or something to make the connection...Here's how:
    1. Remove the small wire from the solenoid (the one that attaches with a spade connector). Leave the big wire connected.
    2. Use a pliers/screwdriver/etc to connect the big bolt to the small spade connector.
    3. Make sure the key is on, and the starter should rotate when contact is made...there will be some sparks when you make the connection, but that is normal for this procedure.
  6. Now, if the starter rotates and you know that you have a good battery and starter button, then only one of two things can be the culprit: either the solenoid is bad or the starter relay is bad.
  7. Start with the relay. My original relay went bad and was replaced with a generic relay. It looks different from the original and won't mount the same, but works great.
  8. If that doesn't fix the problem (at least you now have a cheap spare), it is time to address the solenoid (which is a more expensive replacement part). I don't see any harm in taking the solenoid apart and cleaning things up, that may correct the problem.
  9. If cleaning things up doesn't fix the problem, get a new solenoid.

How to bench test the starter and solenoid

I extracted this information from Bruce Giller off of the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!).

You can bench test the starter off the bike. Clamp it in a vise for there is no point in trying to hold it with your hands; lots of torque. Get a well-charged battery and some jumper cables. Clip the negative to the body of the starter.

Test the solenoid: apply the positive cable to small wire connection (usually a spade type) on the solenoid; you are playing the part of the starter switch. The solenoid should click loudly and throw the ring teeth engagement gear out into the nose of the starter. The starter should not turn.

Test the starter: now apply the positive cable to the big nut on the solenoid that was NOT used for the battery cable on the bike. Here you are bypassing the solenoids' internal T-bar electrical connector and feeding current directly to the starter. The starter should whirrrrr confidently but the ring teeth engagement gear should not budge.

If both components work independently, you can bench test the starter as a whole. Clip the positive cable to where the bikes' battery cable used to attach (big nut). Get a small jumper wire and attach one end to the positive cable and the other to the solenoid connection. Now the solenoid should kick out the engagement gear AND the starter should turn.

How the starter works and more troubleshooting

I extracted this information from Patrick Hayes off of the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!).

Look at how the system operates. It must be a clear, two-step process. When you hit the button, the relay and then the solenoid get energized. The solenoid pulls its core inward, which pushes the starter gear forward through a pivot lever. The starter motor is not yet energized and does not yet spin.

As the pinion gear moves forward, the forward edge of its teeth are supposed to impact against the rear edge of the ring gear teeth. Both sets of teeth should be angled or tapered in some way to discourage a direct, face-to-face tooth hit. At the point of impact, the pinion should be forced to rock one way or the other to slide between mating ring gear teeth.

As the teeth fully mesh and engage, the huge contacts down at the back end of the solenoid inside its cap come into play. When these contacts hit, the starter windings themselves become energized and the motor starts to spin.

So, you have one of two problems if the starter does not always cleanly engage the ring gear.

First, is there some reason that the gear teeth do not embed? Has this error caused the teeth to grind against each other, square off, and exacerbate face-to-face locking? Can you get at the damaged teeth with a dremel grinder and restore a pointed face condition?

Second, is the starter being energized to spin before the gears are meshed? And here again we have two potential problems. Somehow the starter is getting juice before the gears are meshed.

First, has there been enough wear to the pivot and the various mechanical points of the lever system so that it is not pushing the pinion gear as far forward as it used to? Not sure how to repair that, but you could remove the lever and have a little weld dab added to it to restore original thrust dimension.

Second, has someone repaired, cleaned or replaced this solenoid? Was an alternate substitute solenoid used? If it is the original solenoid, and it was cleaned or repaired, was the original cap gasket saved or reproduced? The physical position of the solenoid rear cap (and thus its internal contacts) are critical to the design of this system. If you move the cap slightly forward (by omitting the cap gasket) you allow the starter contacts to come into play before the plunger thrust is complete. If you use an alternate solenoid, the dimensions for thrust and contact may not be completely accurate.

I would suggest a thorough tooth inspection and some lubrication of the pinion shaft to get the gear sliding easier. You can run the solenoid repeatedly on the floor with some test wire and observe its action. Just be sure to disconnect the heavy starter lead so you don't energize that spin or the motor will jump all over the place.

I would suggest a removal and very thorough inspection of the pivot system and the fork face of the pivot against the pinion gear. Is there some substantial wear and can it be improved or corrected?

I would suggest disassembly of the solenoid and the addition of a double or triple thick gasket between the end cap and the solenoid body. By adding gasket thickness here, you are moving the motor contacts aft and delaying the instant point of energizing the starter. The plunger has to go deeper before it makes the motor spin. Perhaps by stacking gaskets, you can delay it long enough to get deeper tooth penetration before spin. At any rate, what you have now is a rotary grinder and you are damaging the face of the pinion and ring teeth. By doing so, you are making the gear contact position worse as it respects the internal solenoid contact position. You have to get tooth penetration BEFORE spin. Doing the gasket stack might be enough to counteract the tooth wear already in place.

One last thought. You might ignore ALL of the above and just inspect the wiring at the starter and solenoid. You maybe haven't done something to short this wiring in some way, or hooked it up incorrectly so that the thrust action and the spin action are happening simultaneously? That would be a case for failure for sure. You have to separate these two functions in time and space. The starter relay ONLY energizes the solenoid. It is the action of the solenoid which energizes the starter windings. I'm trying to imagine how you could hook up contacts incorrectly to get the motor spinning by the relay circuit rather than by the solenoid circuit. Could happen I suppose.

Also, the floating contact on the back end of the solenoid plunger should be a spring loaded bar. Might be possible to lift that bar against its spring and insert something like an o-ring or split washer onto the stem which would effectively move this floating contact forward and thus require a deeper solenoid core penetration before starter contact. This would then require deeper penetration of the pinion/ring pair before spin. There is no spin action here and not all that much heat, so an o-ring might give you the adjustment you seek.

Starter and solenoid repair (Bosch)

I've been meaning to rebuild a couple starters and solenoids I've had for quite some time now. One functioned perfectly but needed cosmetic improvement. That is the starter you'll see pictured below. The solenoid on the other starter functioned fine, but the starter did not turn. Cleaning up the commutator solved that problem.

  1. Always start with a spotless work area!

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  2. OK, that's much better :> Here is the crusty specimen. Time to get started.

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  3. First, remove the wire connecting the starter to the solenoid.

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  4. When you are reassembling, you can reference the terminals so you make sure you align the proper terminal on the solenoid.

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  5. Now remove the screws the secure the solenoid to the starter.

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  6. This is what they look like. The wetness is from PB Blaster...expect to soak these and use an impact driver (the kind with a hammer) to get them unstuck. Upon reassembly, be sure to use loctite on these screws. If you don't, you run the real risk of them loosening up and falling out.

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  7. Remove the solenoid from the starter. Note how the hole in the solenoid's arm fits around the lever.

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  8. Here is a close up picture of the solenoid arm and plunger. I screwed the screws back in a few threads so I wouldn't lose them.

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  9. This nut secures the bolt that acts as a pivot for the arm that engages and disengages the bendix with the ring gear. You should be able to move the arm back and forth and watch the bendix (starter gear) slide back and forth.

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  10. Remove the nut and bolt. You won't be able to withdraw the arm just yet.

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  11. Next, remove the screws that secure the small rear cover.

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  12. Pull it off and this is what you'll see.

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  13. Withdraw the "U" shaped retainer from its slot.

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  14. Withdraw the shimming washer.

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  15. I first thought this was just one washer. But while I was cleaning everything up, I found it was actually a stack of 3 washers stuck together: 1 thick and 2 thin.

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  16. Remove the rubber seal.

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  17. Now remove the big screws. PB Blaster is your friend.

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  18. With the big screws removed, you can pry off the big end cap. Just a twist with a small screw driver is all mine needed.

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  19. Wiggle it off. It only fits one way.

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  20. Here is what is inside.

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  21. Here are all the parts for the top in the order in which to reassemble them.

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  22. There are 4 brushes total. 2 are secured to the brush plate and need not be removed. The remaining 2 are soldered to the field coils and must be removed. Just pry the spring back and pull the brush out.

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  23. Here the brush is removed.

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  24. Now the brush holder just slides off...you can get a better view of 2 brushes that are attached to the field coils.

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  25. Here is a view of the brush holder from the underside. It doesn't matter how it goes back on as the connections are identical.

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  26. Now you can pull the main body off.

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  27. Here it is removed. It only goes back on one way...I didn't get a picture of it, but there is a relief for the little rubber piece that fits between the starter and solenoid.

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  28. Now you can withdraw the winding. It comes right out and may bring the engagement arm along with it.

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  29. Here is how the engagement arm is supposed to engage the bendix. It is reversible so don't worry about right side up or anything like that.

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  30. Here is that little rubber piece that fits between the starter and solenoid holes. Pluck it right out.

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  31. To remove the bendix, use a 13 mm 1/4" drive deep-well socket to drive the steel collar down off of the wire ring. Tap the socket with a hammer.

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  32. Now pry off the wire ring.

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  33. And here is the bendix. I pulled it off as an exercise to see if I could do it, but I wouldn't bother with it unless it was suspect. It is very difficult to get the steel collar back around the ring. I spent more time doing that than anything else. It finally work after a spent a lot of time bending the wire ring with a pliers to get it very close to the size of the recess. Doable but not fun.

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  34. And here are the 3 pieces.

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  35. The winding. No need to drive the shaft out...I'm not that curious! That is it for the starter...from here you can clean up the commutator (the part that the brushes run on) with some fine sandpaper. You can also replace the brushes with new ones. Just a bit of soldering will take care of that. I gave everything a bath in some degreaser and then used my wire wheel to clean up the nasty exterior bits.

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  36. Alright, onto the solenoid. Remove the 2 screws that secure the cap. They may be covered in some silicon glue that you'll have to dig out first.

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  37. Here are the screws.

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  38. Now heat up the connections with a soldering iron. Once the solder has liquefied, pull upward on the cap with your hand. Then do the other side. Move back and forth until the cap comes free.

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  39. Here is the cap as it was removed.

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  40. A look at the contacts inside the cap. Clean these up well. I like to use a tiny wire wheel on my Dremel tool. Then remove any residue with a cleaner (like rubbing alcohol or carb cleaner or such).

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  41. Here is how the cap goes back on. In the picture I'm holding it backwards...so don't get confused. The side that has two wires angling up to the other (LEFT side in the photo) goes to the terminal on the cap with the spade connector. You can see these two wires better in the photos above. Don't get this wrong or you'll have to swap it back around.

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  42. Carefully remove the first cardboard shim.

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  43. Carefully remove the second cardboard shim. Yes, I found two of these on mine. Combined thickness was 1.5 mm or 0.6 in. Be very careful with these and do not lose or destroy them. The thickness they provide is critical. If they are totally destroyed, replace them with shims of identical thickness.

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  44. As usual, assembly is the reverse of disassembly. Be sure to use anti-seize on all of the threads EXCEPT for the bolts that secure the solenoid to the starter body...use blue LOCTITE on those. Put some grease on the bushings and on the shaft where the bendix slides.

    Here is the finished starter and solenoid reassembled and painted. I painted the starter with black truck bed liner in a spray can (thanks to Mark Etheridge of Moto Guzzi Classics for that tip) and I primed and painted the solenoid body with gloss black paint. Stainless steel washers and nuts at the rear of the solenoid complete the project. All in all, I was able to rebuild two starters/solenoids in about four hours of time one humid Florida Saturday afternoon in August, 2006.

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Voltage regulator cross-references

I extracted some of this information from the old Topica Loopframe_Guzzi news group (which has now moved to Yahoo!).

Bosch Generator

Electronic voltage regulators (not original)

Thanks to Charlie Mullendore of Antietam Classic Cycle for providing this information on the Yahoo! Loopframe_Guzzi news group. In Charlie's own words:

Same bike also needed a voltage regulator and I've had less than stellar results with the usual Autozone/Advance Auto supplied units for Bosch generators. Had two fail within the first month of use. This time I decided to use the same Bosch electronic voltage regulator: (Part Number 111903803D) I installed on my '72 Ambo "Sophia". It's been on there for three years with zero problems, begins full output at a lower rpm than the mechanical units and actually costs about the same.

This voltage regulator is available from Wolfsburg West.

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The Bosch electronic voltage regulator, part number 111903803D.The Bosch electronic voltage regulator, part number 111903803D.

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Mechanical (left) vs. electronic (right) wiring comparison on a Volkswagen beetle. Photo courtesy of Andy (glutamodo) on TheSamba.com VW forum.Mechanical (left) vs. electronic (right) wiring comparison on a Volkswagen beetle. Photo courtesy of Andy (glutamodo) on TheSamba.com VW forum.

Mechanical voltage regulators (as original)

The voltage regulator listed below was used in many Dodge vehicles in the 60's and Volkswagen Beetles from 1959 to 1979, so if you can't remember the part number, perhaps you can remember a 1969 Dodge Monaco or a 1971 Volkswagen Beetle.

  • Advance Auto Parts (GP Sorensen): 265002. NOTE: This unit is no longer available. See below.

    I had this unit installed on my Ambassador with a Bosch generator and it worked great. It bolts on without any modifications and wiring it up is simple (see images below for specific wiring connections).

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  • Advance Auto Parts (BWD Automotive): R582
  • Advance Auto Parts (BWD Automotive): R582P
  • Advance Auto Parts (Niehoff Ignition): WA704CS
  • Advance Auto Parts (Standard Motor Products): VR39

The voltage regulator was used on the following vehicles:

Make & ModelFirst YearLast Year
Alfa Romeo Berlina19691971
Alfa Romeo Duetto 160019671968
Alfa Romeo Giulia Sprint19671968
Alfa Romeo GT Veloce19691973
Alfa Romeo GTV19671968
Alfa Romeo Spider19691973
Porsche 91219671969
Saab 9519601963
Saab 9619611963
Volkswagen 4121973
Volkswagen Beetle19671973
Volkswagen Campmobile1970
Volkswagen Fastback19661973
Volkswagen Karmann Ghia19671973
Volkswagen Squareback19671973
Volkswagen Super Beetle19711973
Volkswagen Thing19731974
Volkswagen Transporter19661971

Magneti Marelli Generator

  • Advance Auto Parts (GP Sorensen): VR203. NOTE: This unit is no longer available. See below.

    This is the unit that Keith Ruff installed on his loop during the 2005 National rally in New Cumberland, WV. It works great.

  • Advance Auto Parts (Niehoff): FF150E

    Thanks to Charlie Mullendore of Antietam Classic Cycle for graciously providing me with updated information about the above voltage regulator. In Charlie's own words:

    There's been a change in what voltage regulator is offered by Advance Auto. They no longer stock the GP Sorensen VR203 unit. After perusing the Advance Auto website and looking around elsewhere last night, I've come to the same conclusion - the FF150E is really what I want.

    Advance Auto shows the Niehoff FF150E on their website, but when you go into the store and ask for that part no. they try to give you a fuel filter. All of the others on their website seem to be unavailable - when the counter person checked they all came up "NLA - use Borg-Warner R400Z" (which is for alternators!). Could be this is a "computer glitch" or "operator error" on the part of the counter person, who knows? Didn't even try ordering the FF150E online - see below.

    Called Auto Zone - I asked for one for a '62 Ford Falcon, they could get a Wells VR603 in one day for $34.99, but I elected to order it on their website since I wouldn't be back into Hagerstown until Monday the 15th. Ordered Monday, arrived Thursday, total cost $42.37 with shipping and tax. Looks identical to the Advance Auto Niehoff FF150E, they're probably all made by the same company. Made in the USA! Wow! 3 month warranty. Installed today and it works great - peaks out at 14.1 volts. Of course, you do have to make a mounting adapter plate, but it wires up exactly the same.

    BTW, NAPA and other auto parts stores can get the same thing but charge as much as $90 for it!

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The voltage regulator was used on the following vehicles:

Make & ModelFirst YearLast Year
Ford Club1957 1962
Ford Club Wagon1962
Ford Country Sedan19571962
Ford Country Squire19571962
Ford Courier Sedan Delivery19571960
Ford Custom1957
Ford Custom 30019581960
Ford Del Rio Wagon19571958
Ford Econoline19611964
Ford F Series19561959
Ford F-100 Pickup19601964
Ford F-250 Pickup19601964
Ford F-350 Pickup19601964
Ford Fairlane19571962
Ford Falcon19601962
Ford Falcon Sedan Delivery19611962
Ford Galaxie19591962
Ford Ranch Wagon19571962
Ford Ranchero19571964
Ford Skyliner19571959
Ford Starliner19601961
Ford Sunliner19571962
Ford Thunderbird19571962
Ford Victoria19571962
Lincoln Capri19561959
Lincoln Continental19581960
Lincoln Lincoln Series1960
Lincoln Mark II19561957
Lincoln Premier19561960
Mercury Colony Park19571962
Mercury Comet19601962
Mercury Commuter19571962
Mercury Country Cruiser19591960
Mercury Medalist1958
Mercury Meteor19611962
Mercury Montclair19571960
Mercury Monterey19571962
Mercury Park Lane19581959
Mercury Turnpike Cruiser1957
Mercury Villager1962
Mercury Voyager19571959

Wiring diagram - headlight relay

The following schematic shows how to utilize relays for the headlight high and low beam circuits. This simple modification does wonders for extending the life of your switches.

33 KB1 page

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Wiring diagram - relays

Relays are very beneficial anytime you don't want to run a large amount of current through a switch that isn't designed to handle it. Here's how to wire a relay.

Every relay has terminals that are marked. Usually, there are either 4 or 5 terminals, with the following markings:

  • The terminal numbered 86: This is the "switch" terminal. Normally this is the wire that would go directly from the switch to whatever device you are operating. Now that a relay is involved, the wire from the switch would run directly to this terminal.
  • The terminal numbered 85: This is the "ground" terminal. This is a new wire. It works in conjunction with the terminal numbered 86 and completes the "switching" circuit.
  • The terminal numbered 30: This is the "power-in" terminal. This is a new wire. It supplies power from the fuse block (usually).
  • The terminal numbered 87: This is the "relayed" or "normally open" terminal. This is a new wire. It connects directly to whatever device you are operating.
  • The terminal numbered 87 (may or may not be present): This is a duplicate "relayed" or "normally open" terminal. If you wanted to relay two items with one switch, this additional terminal could be useful.
  • The terminal numbered 87a (may or may not be present): This is the "non-relayed" or "normally closed" terminal. If you wanted to turn something off whenever the relay was activated, then this terminal could be useful.

I think it is most useful to think of the relay as a light-duty "switch" that operates a heavy-duty "switch". Here's how it works. When you activate a hand-operated switch (headlight switch, driving light switch, starter button, etc.), you are completing the circuit between terminals 85 and 86 in the relay. This is the light-duty "switch" and only requires only a very small amount of amperage to be activated. Therefore, it is very gentle on the hand-operated switch and causes very little arcing across the contacts. Now, once the circuit is complete between terminals 85 and 86, the relay operates a heavy-duty "switch" between terminals 30 and 87. This heavy-duty "switch" is able to handle a lot of amperage without the destroying the contacts (typically 20, 30, or more amps for the automotive industry). Using a relay, you are able to operate a device that draws a lot of current with a hand-operated switch designed only for low current devices.

Many modern motorcycles come equipped with relays for numerous devices, such as starters and lights. However, if you are adding additional driving lights to a modern bike, or upgrading the lights on an older bike with higher wattage bulbs, you'll want to install relays to protect your expensive hand-operated switch gear.

Dan Prunuske sells 25 amp micro relays and has a lot of good information on his website.

Here is a list of various part numbers that may help you track down a generic relay:

  • Borg Warner R3062
  • Borg Warner R681
  • Bosch 0332019150
  • GP-Sorensen MR38
  • Echlin ECHAR230
  • Echlin ECHAR201
  • Mileage Plus MPEAR201SB
  • Wells 19861

Wiring diagrams (very large and easy to read)

To me, there are few things more frustrating than struggling to read a wallet-sized wiring diagram. These enlarged wiring diagrams print across multiple pages. Once you tape the pages together, you'll have a very large wiring diagram that is easy to read. I attach them to the back side of a door in my garage.

Carl Allison has created many wonderful, high quality wiring diagrams for Guzzis. His wiring diagrams are hosted here as well as on the GuzziTech website.

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Wiring diagram - starter relay

The following schematic shows how to wire a relay for the starter circuit.

18 KB1 page

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Wiring diagram - turn signals

The following schematic shows how to wire turn signals. This will be most useful to owners of V7 / V700 and Ambassador models, which did not come originally equipped with turn signals. It is also useful for anyone installing a new wiring harness - as even the pre-made looms do not come with the turn signal wires.

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