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Moto Guzzi Round Head Tonti Frames

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Purpose, disclaimer, and other resources

Updated: 2008 Oct 01

Purpose

The purpose of this page and the information it contains is to provide useful or hard-to-find information about the round head Moto Guzzi Tonti frame motorcycles. The term "Tonti" refers to the engineer who designed the frame, Lino Tonti.

Disclaimer

I have done my best to present correct and accurate information. However, I do not consider myself an expert in the area of Moto Guzzi motorcycles nor round head Tonti framed models in particular. If you find this information useful, I'm glad to be of service. If you see something that is incorrect, I'd appreciate it if you would send me a quick email detailing the mistake. If you use any of the information I have provided, you do so at your own risk. I take no responsibility for the accuracy of nor the consequence of using any content on this page.

Other resources

Of course, all of this information can be gleaned from alternative sources. For reading material, get the factory workshop manuals, the factory spare parts catalog, the Haynes book (Moto Guzzi 750, 850 & 1000 V-Twins Owners Workshop Manual; ISBN 0856963399), or Guzziology by Dave Richardson. For serious online discussions, try the GuzziTech and Guzzi Exchange Australia news groups. For parts, I recommend MG Cycle, Moto Guzzi Classics, Moto International, or your local dealer. ebay can also good place to look. If you want to be a member of an excellent motorcycle club, I recommend the Moto Guzzi National Owners Club.

 

Alternator - A 55 Amp Alternative

Updated: 2009 Sep 11

Thanks to Timothy Brunner for sending me this information in a private communication. Tim learned about this set up from a gentleman named Tord in Sweden. In Tord's own words:

I attach a couple of pictures who describes in pictures a modification to a BOSCH 55 Amps alternator, the three lights really beam-flashes now.

The fix is a easy way to do, just dismantle the front cover and weld a ring ( i can give you the measurement) machine the cover in a mill or turn it in a lathe to 110mm I think it was. then bore a new thread holes, Then the shaft must modified the, I don't remember what it was. But I can give you the exact drawing on the job if you want. it was my father who did the job last summer. And it works perfect, And NO the plastic cover DOES NOT move forward, it depends on that he welded the ring a little bit backward so it was lots of materials to turn away and lot of materials to dip down the alternator in.

I attached more pictures to explained for you, maybe you understand (my English isn't so good)

As you see the BOSCH original alternator shaft must turn away some materials, turn a cone that match as in a actual length. It must match the surrounded alternator. and the surrounded alternator dips in the cover, about some measure that I don't remember, but if you want to know, don't hesitate to contact me in an week or something, then I have heard with my father about the right way to do. Then maybe you can let someone do it in a factory. /Tord

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

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Photo courtesy of Tord.Photo courtesy of Tord.

Brake line replacement

Updated: 2008 Sep 13

Thanks to Karl Kologiski for sending me this information in a private email. In Karl's own words:

Here is a great place to get brake lines. My dad got a set for his guzzi and they were terrific with the swivel ends. They can also do custom lines and older bikes. You just send them your old lines as a pattern.

Spiegler Performance Parts

Brochure - V7 Sport

Updated: 2009 Dec 07

Download Name and LinkFile SizeNumber of Pages in File
2,376 KB3 pages

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

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.

Crush washers

Updated: 2008 Mar 03

Fiber or aluminum crush washers are used to make seals in numerous locations. Here are the applications and inside diameter sizes used on nearly all round head Tonti frame models:

Functional areaApplicationPart numberInside diameterQuantity needed
EngineFill plugMG# 9510070920 mm1
EngineDrain plugMG# 9510070920 mm1
EngineBreather return line banjo boltMG# 1200640012 mm2
EngineOil feed lines to heads banjo boltsMG# 121542008 mm6
EngineOil pressure switchMG# 1200640012 mm1
5 speed transmissionFill plugMG# 9510070920 mm1
5 speed transmissionDrain plugMG# 1052890010 mm1
5 speed transmissionLevel plug

not applicable to I-Convert

MG# 1052890010 mm1
Rear driveFill plugMG# 9510070920 mm1
Rear driveDrain plug

not applicable on models equipped with deep sump rear drives

MG# 1052890010 mm1
Rear driveLevel plugMG# 1052890010 mm1

The I-Convert uses many additional crush washers. Here are the applications and inside diameter sizes for it:

Functional areaApplicationPart numberInside diameterQuantity needed
EngineATF oil pressure relief valve on engine timing coverMG# 1816115014 mm1
EngineATF oil pump inlet on engine timing cover

left side

MG# 1816115014 mm2
EngineATF oil pump inlet on engine timing cover

right side

MG# 1200640012 mm2
ReservoirATF return line from cooler to reservoir

top fitting

MG# 1200640012 mm2
ReservoirATF return line from to reservoir

middle fitting

MG# 1200640012 mm2
ReservoirATF inlet line to oil pump from reservoir

bottom fitting

MG# 1814435018 mm2
TransmissionConverter inlet line from ATF oil pump

top banjo bolt on right side of transmission

Extra crush washer needed to prevent acorn nut from bottoming out

MG# 1200640012 mm3
TransmissionConverter outlet line to oil cooler

bottom fitting on right side of transmission

Extra crush washer needed to prevent acorn nut from bottoming out

MG# 1200640012 mm3
TransmissionConverter return line to reservoir

underneath transmission

MG# 1200640012 mm2
TransmissionDrain line banjo bolt on bottom of transmission bell housingMG# 8 mm2
TransmissionConverter inlet fitting from ATF oil pump

top fitting on right side of transmission

MG# 1816115014 mm1
TransmissionConverter outlet fitting to oil cooler

bottom fitting on right side of transmission

MG# 1200640012 mm1

Dash indicator light improvement

Updated: 2008 Jun 24

I extracted this information from John Wells who posted it on the Yahoo! MGconvert news group. In John's own words:

Convert dash lights are abysmal in daylight. If you lost oil pressure, you'd never know it till the engine seized. You could ride for miles with a turn signal on (not that that's ever happened to me).

Visited superbrightleds.com and replaced all the 1.2 watt "wheat" bulbs with SMD LED High Power 6 lumen 74-xHP wedge base led's. MAN! What a difference!! Idiot lights now visible in bright sunlight. $2.49 per bulb, order same bulb color as lens in dash, NOT WHITE!! (important!)

These bulbs are polarized, so test each light before you reassemble the dash, if it's not working, reverse the bulb in the socket. They fit perfectly. I guess they'd work in SPIII, Cal III, and whatever others use the 1.2W night lites for indicators. For me, it was money well spent. Shipped quickly, also. (The 1157 Luxeon 3W tail light bulbs are great too, same deal, order same color as taillight lens)

More information on ordering and installation:

The lights are a direct replacement for the 1.2W wedge base bulbs. They are polarized, so check function before reassembling. Reverse the bulb in the socket if it's not lit. Be sure to get the high output ones (6 lumen)

Spade blades are attached to a removable plastic socket which holds the wedge-base bulb. Leave wires attached and pull the plastic socket out (No screwing needed!), then pull the bulb straight out of the socket. Then replace and check polarity and function before reassembling dash.

Fork seals

Updated: 2009 Oct 19

The dimensions of the forks seals on my I-Convert are as follows:

  • ID: 34.74 mm
  • OD: 47 mm
  • Width: 9 mm

G5 photos - largely unmolested

Updated: 2009 Oct 21

Thanks to LeRoy (Bob Sharp) sent me these photos when I asked about how the wiring harness was originally routed on my I-Convert. LeRoy acquired the photos from Performance Cycle in Oklahoma City, Oklahoma. Performance Cycle was offering these G5 units for sale on eBay in 2008…both with extremely low miles and largely unmolested (though with parts missing). These photos provide excellent documentation for how Moto Guzzi intended things to be from the factory. Enjoy!

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 1. Photo courtesy of LeRoy (Bob Sharp).G5 1. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

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G5 2. Photo courtesy of LeRoy (Bob Sharp).G5 2. Photo courtesy of LeRoy (Bob Sharp).

Header pipe flange securing studs

Updated: Prior to 2007 Dec 11

The original studs are 8 mm x 1.25 mm x 42 mm. I purchased some replacement 40 mm long 18-8 stainless steel studs from McMaster-Carr (item number 93805A359). They work great although next time I would purchase 50 mm studs and remove the excess as the 40 mm are just a bit short.

I-Convert ATF pump O-ring size

Updated: 2008 Mar 10

The physical dimensions of the o-ring (MG# 90706409) that seals the ATF oil pump to the timing chest is as follows:

  • 40 mm ID x 2.5 mm thick

I-Convert ATF pump seal size

Updated: 2008 Jun 05

The physical dimensions of the seal (MG# 90401423) are as follows:

  • ID: 14 mm
  • OD: 22 mm
  • Width: 4 mm

I-Convert early prototype

Updated: 2009 Aug 10

This one page article is from the February, 1973 edition of Motorcyclist. I've got an original copy. So, if you require a larger resolution scan, please let me know.

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Early prototype of an I-Convert. Motorcyclist, February 1973Early prototype of an I-Convert. Motorcyclist, February 1973

I-Convert replacement oil lines

Updated: 2008 Feb 29

I extracted much of this information from Paul Linn in personal communications.

The operating pressure of the hydraulic oil for the torque converter is 25-29 PSI. Because it is this low, standard oil lines can easily replace the stock lines. There is no need to source new fittings. Just cut the existing pressed-on hose clamps off, replace the hose, and clamp in place. As is mentioned in Guzziology, the line running from the reservoir tank to the inlet (left) side of the hydraulic pump is under suction. Be sure to use a thick-walled hose in this application to prevent it from collapsing.

I-Convert transmission: How it works

Updated: 2010 Apr 02

I extracted this information from Patrick Hayes and Jim VanDenBerghe off of the Yahoo! MGconvert news group.

In Patrick's own words:

First, the Convert has a traditional, two-speed manual transmission. Two gears, low and high. There is no neutral position per se. The only way to obtain a neutral function is to pull in the clutch handle and hold it ( for maintenance purposes you wrap a bungee around it).

Second, this two speed manual transmission is driven by a traditional multi-plate motorcycle clutch. In this case, I think Guzzi stole the clutch bits from either Stornello or Nuovo Falcone.

Third, the clutch and transmission are driven by a a fluid torque converter mounted on the engine flywheel (hence the name CONVERT). At lower rps, the fluid slippage of the torque converter means that you don't have to pull in the clutch at idle. The bike will simply sit and idle until you give it the gas. Think of a humongous moped.

Fourth, because there is a fluid torque converter coupling between the engine and the clutch/transmission, there is very little engine braking effect. You have to use the brakes a lot more than on other motorbikes.

Fifth, the torque converter and the ATF fluid system only operate the drive function. Unlike your automatic transmission car, the fluid system on this motorbike has nothing to do with gears or transmission.

Sixth, the bike will go 0-70 mph in low gear and 0-100 mph in high gear. Obviously, acceleration is a bit sluggish in high gear but many people leave it in high and don't shift for a month.

Seventh, the transmission should not be shifted while the bike is in motion. Select low or high before you start out. If you need to change, stop and change. The purpose of the clutch is to soften the blows or impacts on the gear dog faces when shifting.

Eighth, the basic idea of a torque converter is like this. These are very simplified concepts. You take a chamber and fill it with fluid. Within the chamber are two propeller like devices attached to an input shaft and an output shaft. At low rotation speeds one propeller moves and the other does not. The fluid just swirls and slips around the moving propeller blades. As the rpms are increased, the motion of the first propeller begins to add a lot of fluid drag and force to the second propeller, eventually moving that second propeller. At mid rpm ranges, there is still slippage and the input propeller is spinning somewhat faster than the output propeller. At very high rpms, the slippage becomes almost negligible and the two propellers approach a matching speed synchronization.

Ninth, because of all this slippage in the torque converter, the Convert motorcycle traditionally gets poorer fuel economy than similar standard mechanical motorcycles.

Tenth, because the Convert is mostly driven in high gear, the engine seldom reaches any serious rpm level and more commonly is loping along at lower rpms. An unfortunate side effect may be a poor battery recharge and a gradual decline in battery, requiring an overnight charger boost every week or two.

Patrick's reply to the question, "How come the fluid needs to be under pressure to work? Is it just that it would get too hot if you didn't re-circulate it and cool it?"

You've reached the limits of my knowledge on this one. Perhaps someone understands the SACHS torque converter more completely. As far as I can tell, the fluid doesn't do anything other than transfer drive force from the engine half to the transmission half. The slip and drag of the fluid generates a lot of frictional heat and it has to be circulated through a radiator. Also, any air contamination within the converter would lead to cavitation of the liquid and loss of drive force. Pressurized circulation helps ensure purging of air. I don't think pressurizing the fluid in the converter makes it work any more efficiently. Liquids don't compress much under pressure. I may be wrong and there may be some pressure advantages inside the converter. But, the pressure isn't moving anything (other than the fluid) unlike a car transmission where the pressure is utilized to move clutches, gears, valves, etc.

One other strange component of this torque converter is the central bearing. It has oval rollers rather than round balls. As speed and pressure are applied, these rollers stand up and wedge themselves between the converter and the transmission shaft. When the engine is off, they lay down and release the contact grip between the transmission and the engine. Thus allowing you to roll the bike around without having to combat drag of the drive system.

Some further clarification from Jim VanDenBerghe:

The ATF pump doesn't cause the bike to move. It doesn't "pump" the bike forward. The reason for the pump is to simply circulate the fluid that was warmed up (due to the slippage loss) through the ATF cooler where it is cooled down so it's temp doesn't exceed the maximum design temperature of the ATF fluid.

Those oval rollers are called "sprags". They are used in a lot of auto applications too, and I bet in other power transmission systems. They allow torque to be transmitted in only one direction, i.e. clockwise or counterclockwise, but not in both directions. In the other opposite non-driving direction the two shafts slip without torque being transferred (free-wheels).

I-Convert transmission O-ring sizes

Updated: 2008 Mar 10

Location Part number ID Width
Clutch assembly (in front) MG# 90706600 60 mm 2.5 - 2.6 mm
Clutch assembly (in groove on shaft) MG# 90706158 16 mm 2.5 - 2.65 mm
Clutch assembly (around bearing) MG# 90706473 47 mm 2.6 - 2.7 mm
Input (clutch) shaft MG# 90706188 20 mm 1.85 - 2.0 mm
Output shaft (layshaft) MG# 90706222 22 mm 2.5 - 2.7 mm
Shift shaft MG# 90706108 10.6 14.0 mm 1.85 mm

I-Convert transmission repair

Updated: 2010 Aug 10

Here is the series of photos I took during the disassembly of the transmission on my I-Convert project bike. Assembly is pretty much the reverse. It should go without saying that all the parts were fastidiously cleaned and new o-rings and seals were fitted throughout. From a 10,000 foot view perspective, here is the order of events.

  1. Separate the converter cover from the two speed gear box.
  2. Remove the clutch input hub assembly from the converter cover.
  3. Disassemble the clutch input hub assembly.
  4. Remove the clutch assembly from the two speed gear box.
  5. Disassemble the two speed gear box.

Converter cover disassembly

The transmission is really two separate units that are bolted together and interface with one another through dry clutch plates. The "converter cover" is the front unit, and it is bolted to the rear "gear box" unit. I began disassembly by removing the converter cover from the 2 speed gear box.

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Start by removing the bronze bushing from the shaft so it won't fall out later.Start by removing the bronze bushing from the shaft so it won't fall out later.

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It just slides out. During reassembly the only thing that matters is that the notches face the front.It just slides out. During reassembly the only thing that matters is that the notches face the front.

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Remove the 6 bolts that secure that converter cover to the 2 speed gearbox. The converter cover will then separate from the 2 speed gearbox.Remove the 6 bolts that secure that converter cover to the 2 speed gearbox. The converter cover will then separate from the 2 speed gearbox.

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This is the rear side of the converter cover. The splined piece is the clutch input hub that interfaces with the clutch plates.This is the rear side of the converter cover. The splined piece is the clutch input hub that interfaces with the clutch plates.

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In order to remove the clutch input hub assembly from the convert cover, you need to remove 5 bolts. Rotate the clutch input hub until the bolts are visible through the access holes.In order to remove the clutch input hub assembly from the convert cover, you need to remove 5 bolts. Rotate the clutch input hub until the bolts are visible through the access holes.

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Remove each of the 5 bolts and withdraw the assembly. The complete clutch input hub assembly should slide right out of the converter cover.Remove each of the 5 bolts and withdraw the assembly. The complete clutch input hub assembly should slide right out of the converter cover.

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Here is the seal (MG# 90404563) and several of the passages that must be aligned with the corresponding passages in the clutch input hub assembly during reassembly.Here is the seal (MG# 90404563) and several of the passages that must be aligned with the corresponding passages in the clutch input hub assembly during reassembly.

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Drive the seal out (MG# 90404563).Drive the seal out (MG# 90404563).

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Here is how the seal (MG# 90404563) must be positioned during assembly.Here is how the seal (MG# 90404563) must be positioned during assembly.

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A view of the rear side of the converter cover.A view of the rear side of the converter cover.

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Note the use of multiple aluminum crush washers to prevent the acorn nuts from bottoming out before making a tight seal.Note the use of multiple aluminum crush washers to prevent the acorn nuts from bottoming out before making a tight seal.

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A closer view of the fittings for the oil lines. Notice the bottom one is a smaller diameter than the top one. I removed both of these fittings. That about covers the removal and disassembly of the converter cover.A closer view of the fittings for the oil lines. Notice the bottom one is a smaller diameter than the top one. I removed both of these fittings. That about covers the removal and disassembly of the converter cover.

Clutch input hub disassembly

With the clutch input hub removed from the converter cover, we can disassemble it.

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Now we turn our attention to disassembling the clutch input hub. Start by removing this o-ring (MG# 90706600).Now we turn our attention to disassembling the clutch input hub. Start by removing this o-ring (MG# 90706600).

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Note the holes that must align with the passageways in the converter cover during assembly. You can see that I've already started to separate the two halves that were held together by the 5 bolts.Note the holes that must align with the passageways in the converter cover during assembly. You can see that I've already started to separate the two halves that were held together by the 5 bolts.

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Here is another hole that must be aligned with the passageways in the converter cover during assembly.Here is another hole that must be aligned with the passageways in the converter cover during assembly.

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Completely separate the two halves that were held together by the 5 bolts. I was able to accomplish this using small screwdrivers and careful prying.Completely separate the two halves that were held together by the 5 bolts. I was able to accomplish this using small screwdrivers and careful prying.

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Remove the o-ring (MG# 90706473) from the front half.Remove the o-ring (MG# 90706473) from the front half.

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This hole in the front half is supposed to be plugged (the other hole on the opposite side should not be plugged).This hole in the front half is supposed to be plugged (the other hole on the opposite side should not be plugged).

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Remove the o-ring (MG# 90706158) from the shaft.Remove the o-ring (MG# 90706158) from the shaft.

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Remove the snap ring (MG# 90271020) from the shaft. This snap ring keeps the bearing in place.Remove the snap ring (MG# 90271020) from the shaft. This snap ring keeps the bearing in place.

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Pull the bearing (MG# 92201220) from the shaft. If I remember correctly, I needed to use a press (or puller) to pull up on the bottom half (with the 5 bolt holes). This is necessary because the bearing sits inside of it and you can't get a grip on the bottom of the bearing. Just be careful not to bend the bottom half when you use your press (or puller).Pull the bearing (MG# 92201220) from the shaft. If I remember correctly, I needed to use a press (or puller) to pull up on the bottom half (with the 5 bolt holes). This is necessary because the bearing sits inside of it and you can't get a grip on the bottom of the bearing. Just be careful not to bend the bottom half when you use your press (or puller).

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Remove the bearing (MG# 92201220).Remove the bearing (MG# 92201220).

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Remove the seal (MG# 90402535), note the direction that it must be installed. I'm certain I removed the seal after I'd removed the plate. I just took the picture here to be clear about assembly order, etc.Remove the seal (MG# 90402535), note the direction that it must be installed. I'm certain I removed the seal after I'd removed the plate. I just took the picture here to be clear about assembly order, etc.

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Remove the bottom plate.Remove the bottom plate.

Clutch basket disassembly

The clutch basket needs to be removed before we can disassemble the gear box.

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With the converter cover removed and the clutch input hub disassembled, I turned my attention to the 2 speed gearbox. Here is the stack of clutch plates installed.With the converter cover removed and the clutch input hub disassembled, I turned my attention to the 2 speed gearbox. Here is the stack of clutch plates installed.

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Here is the snap ring that must be removed. In order to do that, we must first take the pressure off of the clutch and intermediate plates.Here is the snap ring that must be removed. In order to do that, we must first take the pressure off of the clutch and intermediate plates.

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I used the clutch throw out bearing adjustment nut at the rear of the transmission to take the pressure off of the clutch and intermediate plates.I used the clutch throw out bearing adjustment nut at the rear of the transmission to take the pressure off of the clutch and intermediate plates.

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First, remove the smaller jam nut from the back of the transmission.First, remove the smaller jam nut from the back of the transmission.

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I also removed the adjustment nut and the lever so I could clean and lubricate the threads. Also, I wanted to remove the rubber boot from the lever so it would be easier to tighten the adjustment nut.I also removed the adjustment nut and the lever so I could clean and lubricate the threads. Also, I wanted to remove the rubber boot from the lever so it would be easier to tighten the adjustment nut.

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I put the lever back on with the adjustment nut. I then tightened the adjustment nut to compress the clutch springs and take the pressure off of the clutch plates. Go slow here. You may need to completely remove the adjustment nut, then clean and lubricate the threads so that you don't destroy the threads in the process.I put the lever back on with the adjustment nut. I then tightened the adjustment nut to compress the clutch springs and take the pressure off of the clutch plates. Go slow here. You may need to completely remove the adjustment nut, then clean and lubricate the threads so that you don't destroy the threads in the process.

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With the large snap ring removed, you can withdraw all of the clutch and intermediate plates.With the large snap ring removed, you can withdraw all of the clutch and intermediate plates.

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Here is the stack of clutch and intermediate plates. I kept them in the original order throughout cleaning and reassembly. It shouldn't matter, but when reusing used parts I like to error on the side of same-ness.Here is the stack of clutch and intermediate plates. I kept them in the original order throughout cleaning and reassembly. It shouldn't matter, but when reusing used parts I like to error on the side of same-ness.

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Remove the adjustment nut.Remove the adjustment nut.

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And withdraw the clutch throw out bearing pull rod from the front of the gearbox.And withdraw the clutch throw out bearing pull rod from the front of the gearbox.

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Another view of the pull rod being removed.Another view of the pull rod being removed.

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The throw out bearing (MG# 92204217) came out easily.The throw out bearing (MG# 92204217) came out easily.

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Another view of the throw out bearing (MG# 92204217) being removed.Another view of the throw out bearing (MG# 92204217) being removed.

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This is the special insert that fits inside the throw out bearing (MG# 92204217).This is the special insert that fits inside the throw out bearing (MG# 92204217).

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Remove the pressure plate. Note the 6 springs and the thin washers. The washers fit within the recesses of the pressure plate, not in the basket.Remove the pressure plate. Note the 6 springs and the thin washers. The washers fit within the recesses of the pressure plate, not in the basket.

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Another view of the pressure plate with thin washers and springs.Another view of the pressure plate with thin washers and springs.

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The lip of the nut will have been peened into the slot in the shaft. Pry the peened portion away from the shaft.The lip of the nut will have been peened into the slot in the shaft. Pry the peened portion away from the shaft.

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And remove the nut.And remove the nut.

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Remove the basket. Mine came off pretty easily without much fuss.Remove the basket. Mine came off pretty easily without much fuss.

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A seal runs on this surface, be sure to clean and dress it properly.A seal runs on this surface, be sure to clean and dress it properly.

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With the clutch basket removed, you can now see the front of the gearbox and the seal.With the clutch basket removed, you can now see the front of the gearbox and the seal.

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Note the seal (MG# 90402838).Note the seal (MG# 90402838).

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And the o-ring (not shown in the parts book). Before we remove the seal or o-ring, however, lets disassemble the gear box.And the o-ring (not shown in the parts book). Before we remove the seal or o-ring, however, lets disassemble the gear box.

Gear box disassembly

With the clutch basket removed from the gear box, we can now disassemble the gear box.

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A view of the rear of the transmission.A view of the rear of the transmission.

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Here is the shift arm and how it was originally positioned.Here is the shift arm and how it was originally positioned.

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We'll start disassembling the gear box by removing the speedometer drive gear.We'll start disassembling the gear box by removing the speedometer drive gear.

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Remove the gear drive.Remove the gear drive.

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And use a small magnet to withdraw the hardened steel washer down inside that hole.And use a small magnet to withdraw the hardened steel washer down inside that hole.

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Set the transmission up on end. Remove the spring loaded plug that holds gear selector pawl in place.Set the transmission up on end. Remove the spring loaded plug that holds gear selector pawl in place.

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Remove the crush washer.Remove the crush washer.

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Withdraw the spring and selector pawl.Withdraw the spring and selector pawl.

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Remove the drain plug along with its crush washer.Remove the drain plug along with its crush washer.

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Remove all of the bolts that secure the cover to the case.Remove all of the bolts that secure the cover to the case.

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Here is the snap ring on the output shaft.Here is the snap ring on the output shaft.

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Remove the snap ring (this could also be removed after the cover is removed).Remove the snap ring (this could also be removed after the cover is removed).

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Remove the cover from the case.Remove the cover from the case.

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The inside of the cover.The inside of the cover.

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The gears inside the transmission.The gears inside the transmission.

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A closer view.A closer view.

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Remove the thrust/shimming washers.Remove the thrust/shimming washers.

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There were two placed to the rear of the bearing.There were two placed to the rear of the bearing.

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Then remove the thrust bearing.Then remove the thrust bearing.

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There was a single thrust/shimming washer in front of the bearing.There was a single thrust/shimming washer in front of the bearing.

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The shift fork assembly is secured to the splined shaft via a pinch bolt.The shift fork assembly is secured to the splined shaft via a pinch bolt.

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Note the alignment of the external shift arm with the nub on the shift fork assembly.Note the alignment of the external shift arm with the nub on the shift fork assembly.

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Remove the pinch bolt.Remove the pinch bolt.

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Withdraw the external shift arm/splined shaft.Withdraw the external shift arm/splined shaft.

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Note the o-ring (MG# 90706108).Note the o-ring (MG# 90706108).

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Remove the input shaft.Remove the input shaft.

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The input shaft and the o-ring that seals the input shaft and the inner race of the bearing. Note that the o-ring is fit outside of the gearbox, in between the clutch basket and the bearing.The input shaft and the o-ring that seals the input shaft and the inner race of the bearing. Note that the o-ring is fit outside of the gearbox, in between the clutch basket and the bearing.

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The bearing retainer is secured by three bolts.The bearing retainer is secured by three bolts.

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Remove the three bolts and the bearing retainer.Remove the three bolts and the bearing retainer.

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This is the puller arrangement I devised to get the rear bearing and the spacer that the seal runs on off of the output shaft. I chose to pull them off as a unit because (a) the spacer that the seal runs on was stuck in place and (b) I did not want to risk damaging the sealing surface of the spacer that the seal runs on. The clamp was very useful to keep the fingers of the puller lodged under the bearing.This is the puller arrangement I devised to get the rear bearing and the spacer that the seal runs on off of the output shaft. I chose to pull them off as a unit because (a) the spacer that the seal runs on was stuck in place and (b) I did not want to risk damaging the sealing surface of the spacer that the seal runs on. The clamp was very useful to keep the fingers of the puller lodged under the bearing.

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Another view of the puller arrangement.Another view of the puller arrangement.

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And a close up view of the puller arrangement.And a close up view of the puller arrangement.

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Here is the spacer that the seal runs on. I was able to clean this up nicely.Here is the spacer that the seal runs on. I was able to clean this up nicely.

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The o-ring (MG# 90706222) remained on the shaft when I pulled the bearing off.The o-ring (MG# 90706222) remained on the shaft when I pulled the bearing off.

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Here is where the o-ring (MG# 90706222) fits: within the front recess of the spacer that the seal runs on.Here is where the o-ring (MG# 90706222) fits: within the front recess of the spacer that the seal runs on.

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Remove the shimming washer.Remove the shimming washer.

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Remove the normal speed gear.Remove the normal speed gear.

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Now the main shaft is easily removed from the front bearing.Now the main shaft is easily removed from the front bearing.

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Remove the shift sleeve. Note which side face rearward and which side faced frontward. The shift sleeve can be reversed to double the life of the engagement dogs.Remove the shift sleeve. Note which side face rearward and which side faced frontward. The shift sleeve can be reversed to double the life of the engagement dogs.

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Note how one side of the engagement dogs is rounded. This is what happens when convert transmissions are shifted at speed. They should always be shifted when the machine is not in motion.Note how one side of the engagement dogs is rounded. This is what happens when convert transmissions are shifted at speed. They should always be shifted when the machine is not in motion.

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A view of the other side of the shift sleeve.A view of the other side of the shift sleeve.

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The output shaft was pretty well stuck in the front bearing and there is no good way to "pry" it out. So, I welded up a small adapter for my slide hammer so that I could pull the shaft out. The end of the shaft is already threaded for 8 mm x 1.25 mm threads, so all I needed to do was weld a bolt onto the end of an adapter. This worked a treat!The output shaft was pretty well stuck in the front bearing and there is no good way to "pry" it out. So, I welded up a small adapter for my slide hammer so that I could pull the shaft out. The end of the shaft is already threaded for 8 mm x 1.25 mm threads, so all I needed to do was weld a bolt onto the end of an adapter. This worked a treat!

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Another view of the puller I used to withdraw the output shaft from the bearing.Another view of the puller I used to withdraw the output shaft from the bearing.

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Another view of the puller I used to withdraw the output shaft from the bearing.Another view of the puller I used to withdraw the output shaft from the bearing.

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Another view of the puller I used to withdraw the output shaft from the bearing.Another view of the puller I used to withdraw the output shaft from the bearing.

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The output shaft (layshaft).The output shaft (layshaft).

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The low speed gear remained in the box.The low speed gear remained in the box.

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Here is the low speed gear back in place on the output shaft (layshaft). Note the shimming washer is still on top of the bearing.Here is the low speed gear back in place on the output shaft (layshaft). Note the shimming washer is still on top of the bearing.

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The shimming washer is now in place on the output shaft (layshaft).The shimming washer is now in place on the output shaft (layshaft).

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Use a seal puller to remove the seal from the case. Be careful not to gouge the case or else you'll have trouble getting the next seal installed and you may have trouble with it sealing properly.Use a seal puller to remove the seal from the case. Be careful not to gouge the case or else you'll have trouble getting the next seal installed and you may have trouble with it sealing properly.

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Here is the removed seal. The lip of the seal presses against the clutch basket.Here is the removed seal. The lip of the seal presses against the clutch basket.

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Press out the front bearing for the input shaft.Press out the front bearing for the input shaft.

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Here is the blind hole bearing puller I used to remove the bearings from the case.Here is the blind hole bearing puller I used to remove the bearings from the case.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Another view of the blind hole bearing puller.Another view of the blind hole bearing puller.

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Removing the bolt from the case. I think the purpose of this bolt was to prevent the shift shaft from rotating too far. I can't recall for sure now, though.Removing the bolt from the case. I think the purpose of this bolt was to prevent the shift shaft from rotating too far. I can't recall for sure now, though.

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Here is the bolt removed.Here is the bolt removed.

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Use a seal puller to remove the output shaft (layshaft) seal from the rear cover.Use a seal puller to remove the output shaft (layshaft) seal from the rear cover.

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Here is the removed seal.Here is the removed seal.

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Use a small driver to drive out the seal from the rear cover. The bearing will come with it. Take care so as to not destroy the bearing (I do not use a blind hole bearing puller on these bearings unless I have to). Use the largest size drive you can fit.Use a small driver to drive out the seal from the rear cover. The bearing will come with it. Take care so as to not destroy the bearing (I do not use a blind hole bearing puller on these bearings unless I have to). Use the largest size drive you can fit.

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Here is the seal and bearing removed.Here is the seal and bearing removed.

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Here is the vent. I never did remove this from the case. Just cleaned it thoroughly in place along with the rest of the case.Here is the vent. I never did remove this from the case. Just cleaned it thoroughly in place along with the rest of the case.

I-Convert transmission seals

Updated: 2008 Nov 25

Output (layshaft) seal

The physical dimensions of this single lip seal (MG# 90403547) are as follows:

  • ID: 35 mm
  • OD: 47 mm
  • Width: 7 mm

Input (clutch) shaft seal - rear

The physical dimensions of this single lip seal (MG# 90401630) are as follows:

  • ID: 16 mm
  • OD: 30 mm
  • Width: 7/6.5 mm

Input (clutch) shaft seal - front (small, fits into transmission case)

The physical dimensions of this single lip seal (MG# 90402838) are as follows:

  • ID: 28 mm
  • OD: 38 mm
  • Width: 7 mm

Input (clutch) shaft seal - front (large, fits into clutch case)

The physical dimensions of this single lip seal (MG# 90404563) are as follows:

  • ID: 45 mm
  • OD: 60 mm
  • Width: 7 mm

Clutch area seal

The physical dimensions of this single lip seal (MG# 90402535) are as follows:

  • ID: 25 mm
  • OD: 35 mm
  • Width: 7 mm

Ignition switch connections

Updated: 2009 Oct 19

The electrical connections on my I-Convert ignition switch are as follows:

  • Terminal 30 - Green
  • Terminal 50 - Brown
  • Terminal 16 - Red
  • Terminal 15/54 - White

Keys for the ignition switch

Updated: 2009 Mar 16

I extracted this information from Stephen Brenton off of the Yahoo! MGconvert news group.

Key blanks are available from Motorcycle Key Blanks. Note your key series and order accordingly.

  • Moto Guzzi 2 - Pre 1995 Moto Guzzi models using key code series 501-1000 and 1501 to 2000.
  • Moto Guzzi 3P - Pre 1995 Moto Guzzi models using key code series E001 to E710.
  • Moto Guzzi 3M - Same as 3P but all-metal.

Main bearing seal sizes

Updated: 2008 Mar 10

Front main seal

The physical dimensions of this single lip seal (MG# 90402839) are as follows:

  • ID: 28 mm
  • OD: 38 mm
  • Width: 7 mm

Rear main seal

The physical dimensions of this single lip seal (MG# 90405367) are as follows (Viton seals with serrated lips are recommended):

  • ID: 53 mm
  • OD: 68 mm
  • Width: 10 mm

Mikuni round slide tuning baseline

Updated: Prior to 2007 Dec 11

Thanks to Mike Tiberio for providing this information. In his own words…

Recently there was a Mikuni carb setup for a SP 1000 on ebay. I bid, but didn't win. I contacted the seller (Steve Braun), and asked if he would share the jetting information he learned in setting them up.

These carbs are available from pro-flo.com for $90 new, but without a baseline, you could easily spend that much buying tuning parts to get this close. He sent me the following info (with selected edits by me).

Here are the particulars for the Mikuni setup for the SP 1000.

  • VM32 round slides
  • 2.5 Cutaways
  • 159P0 needle barrels (I think he means atomizers or needle jets here)
  • 6DH3 needles clipped at the middle position
  • 170 main jets
  • 35 pilots
  • 2.0 air jets

Some notes:

  • The SP1000 was completely stock.
  • Both intake manifolds are # 14115002 (Right Side). The left carb won't fit with stock left manifold, the carb hits the motor.
  • The intake manifolds should be blended on the inside to match the carb opening.
  • The air cleaners are K&N RU-1730.
  • The installation fits very neatly if the battery is not oversized. I used a sealed Interstate unit: Y60-N24AL-B
  • The carburetors came from Stan Smith at Rocky Point Cycle 937-376-9792

Molex® connectors

Updated: 2010 Jan 28

Molex® brand connectors are used in a number of places throughout the wiring harness on the round finned Tonti framed models. While you are unlikely to find these connectors at your local auto parts store, they are inexpensive and easily found at better electronics stores (not Radio Shack). I found them at my local Fry's Electronics (search for .093).

  • The size used is the 0.093" series
  • Extraction tool for 0.093" diameter pins (economy)
    Waldom part number HT-2054 (Waldom is one distributor of Molex products)
    Fry's part number: 1651603
  • Extraction tool for 0.093" diameter pins (deluxe)
    Waldom part number HT-2038 (Waldom is one distributor of Molex products)
    Fry's part number: 1651599
  • Hand crimp tool for 0.093" diameter pins (certainly not professional grade, but it is inexpensive and gets the job done for the hobbyist)
    Waldom part number HT-1919 (Waldom is one distributor of Molex products)
    Fry's part number: 1651588
  • 1 circuit connector with receptacle and plug
    Waldom part number 1619PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651245
  • 2 circuit connector with receptacle and plug
    Waldom part number 1545PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651278
  • 3 circuit connector with receptacle and plug
    Waldom part number 1396PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651304
  • 4 circuit connector with receptacle and plug
    Waldom part number 1490PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651315
  • 5 circuit connector with receptacle and plug
    Waldom part number 1653PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651337
  • 6 circuit connector with receptacle and plug
    Waldom part number 1261PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651359
  • 9 circuit connector with receptacle and plug
    Waldom part number 1292PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651360
  • 12 circuit connector with receptacle and plug
    Waldom part number 1360PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651371
  • 15 circuit connector with receptacle and plug
    Waldom part number 1375PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651382
  • 10 male and 10 female terminals, #20 through #14 wire range (no receptacle nor plug)
    Waldom part number 1189-90 (Waldom is one distributor of Molex products)
    Fry's part number: 1651533
  • 10 male and 10 female terminals, #26 through #16 wire range (no receptacle nor plug)
    Waldom part number 1381-80 (Waldom is one distributor of Molex products)
    Fry's part number: 1651544
  • 10 male and 10 female terminals, #30 through #22 wire range (no receptacle nor plug)
    Waldom part number 1433-34 (Waldom is one distributor of Molex products)
    Fry's part number: 1651555

Oil pump bearing cross-references

Updated: 2008 Mar 03

The physical dimensions of the needle roller bearing (MG# 92252210) for the oil pump is as follows:

  • ID: 10 mm
  • OD: 22 mm
  • Width: 20 mm

Here are various cross-references:

  • FAG NKI 10/20
  • IKO TAFI 102220
  • INA NKI 10/20
  • SKF NKI 10/20
  • SKF (Old No.) NA 102220

Owner's manuals

Updated: 2009 Dec 07

Download Name and LinkFile SizeNumber of Pages in File
5,580 KB78 pages
  • 850 S3 [Italian]
    Thanks to Michael Walker for creating this owner's manual and sending it to me.
3,302 KB59 pages
  • 850 T3 [English]
    Thanks to Michael Walker for creating this owner's manual and sending it to me.
3,667 KB55 pages
  • V1000 Convert [English]
    Thanks to Paul Linn for loaning me an original owner's manual, which I digitized into this pdf.
4,556 KB64 pages
  • V1000 G5 [English]
    Thanks to Michael Walker for creating this owner's manual and sending it to me.
2,630 KB58 pages

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

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.

Rear drive O-ring size

Updated: 2008 Mar 10

The physical dimensions of the o-ring (MG# 90706584) for the rear drive are as follows:

  • ID: 57 mm
  • Width: 2.75 mm

Rear drive seal sizes

Updated: 2008 Mar 10

Large inner seal

The physical dimensions of this single lip seal (MG# 90407085) are as follows:

  • ID: 70 mm
  • OD: 85 mm
  • Width: 8 mm

Small outer seal

The physical dimensions of this single lip seal (MG# 90403850) are as follows (Viton seals with serrated lips are recommended):

  • ID: 38 mm
  • OD: 50 mm
  • Width: 7 mm

The physical dimensions of the seals for the rear drive are as follows:

  • Large inner seal (MG# 90407085): 70 mm ID x 85 mm OD x 8 mm thick
  • Small outer seal (MG# 90403850): 38 mm ID x 50 mm OD x 7 mm thick

Rear wheel cush drive O-ring size

Updated: 2008 Mar 05

The physical dimensions of the o-ring (MG# 90706490) that seals the cush drive to the rear wheel is as follows:

  • 51 mm ID x 2.5 mm thick

Spare parts catalogs

Updated: 2009 Dec 04

Download Name and LinkFile SizeNumber of Pages in File
7,485 KB103 pages
6,244 KB40 pages
8,761 KB63 pages
11,951 KB59 pages
10,006 KB50 pages

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

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.

Steering head bearing cross-references

Updated: 2008 Mar 06

Thanks to Bob Greene for providing key starting information for these cross-references.

The physical dimensions of the tapered roller bearings (MG# 92249225) are as follows:

  • ID: 25 mm
  • OD: 52 mm
  • Width: 16.25 mm

Here are various cross-references:

  • Maryland Metric item no. 30205
  • FAG 30205A
  • RIV 01/02/7205
  • SKF 30205J2
  • SNR 30205
  • STEYR 30205

Swing arm bearing cross-references

Updated: 2008 Mar 06

Thanks to Bob Greene provided key starting information for these cross-references.

The physical dimensions of the swing arm bearings (MG# 92249216) are as follows:

  • ID: 17 mm
  • OD: 40 mm
  • Width: 12 mm

Here are a couple of cross-references:

  • RIV 01/02/5010
  • SKF 639215

The following physical dimensions are slightly thicker, but work just fine and are much easier to source than the original (thanks to Fred on the Yahoo! Loopframe_Guzzi news group for confirming the fitment).

  • ID: 17 mm
  • OD: 40 mm
  • Width: 13.25 mm

Cross-references for the slightly thicker swing arm bearings:

  • Maryland Metric item no. 30203
  • FAG 30203A
  • RIV 01/02/7203
  • SKF (Eur.) 30203A
  • SNR 30203
  • STEYR 30203

Swing arm bearing seal sizes

Updated: 2008 Mar 05

The physical dimensions of the seals (MG# 90403040) for the swing arm pivots is as follows:

30 mm ID x 40 mm OD x 7 mm thick.

Tank badge removal

Updated: 2008 Nov 10

I extracted this information from LeRoy who posted it on the Yahoo! MGconvert news group. In LeRoy's own words:

While I see that you've been successful in removing the badges, here's a tip for future work of this sort. Most auto trim shops and suppliers sell a variety of thin but stiff plastic pry tools that are commonly used for prying apart the many kinds of plastic clips used for automotive interior trim. This sort of tool is perfect for prying off the tank badges. Start gently at one end, but don't pry too hard or you'll tweak the soft metal badge. You'll quickly see where the pins are and can then work them out more easily.

As you've found, the tank badges on Converts (and other Guzzis of this era) have two pins on the rear side that are part of the casting. These have a slight knob on the end that engages with the retainer on the tank and provide the grip. There are two things to be mindful of when preparing to replace the badges:

  1. The badges should have a curve in their profile to match the curvature of the tank. Be careful in tweaking them to help them confirm to this curve as it's possible (likely) to get the pins out of whack with the badge. In this case, the badge won't want to seat back into the retainers as their alignment will be skewed.
  2. Be mindful of paint build-up in the retainer clips. A bit isn't bad as it will aid in the interference fit of the pins. Too much paint build-up will make installation of the badge difficult and you'll be tempted to give it just a bit harder whack to seat it. That's when an "oops" is likely to happen with your fresh paint. Instead, use an X-acto blade to clear out any excess paint and a gentle hand to thump the badge back in place.

Transmission bearing cross-references - 5 speeds

Updated: 2010 Mar 16

All are open (not shielded or sealed).

Note: I have visually verified all of the bearing sizes.

Input/clutch shaft

  • Front of transmission (MG# 92218424):
    • 25 mm ID x 52 mm OD x 20.6 mm thick - this is a double row ball bearing
      • FAG 3205
      • FED 5205
      • ND 5205
      • New Departure 5205
      • RIV 3205 or 2AANOn25
      • SKF 5205
      • SKF (Eur.) 3205
      • STEYR 3205
  • Rear of transmission (MG# 92256218):
    • 17 mm ID x 35 mm OD x 15 mm thick - this is a needle bearing
      • Durkopp 10-2762
      • RIV NAS 17
      • Torrington 10-2762
      • Timken 10-2762

Main/cluster shaft

  • Front of transmission (MG# 92256218):
    • 17 mm ID x 35 mm OD x 15 mm thick - this is a needle bearing
      • Durkopp 10-2762
      • RIV NAS 17
      • Torrington 10-2762
      • Timken 10-2762
  • Rear of transmission (MG# 92201417):
    • 17 mm ID x 47 mm OD x 14 mm thick - this is a single row ball bearing
      • FAF 303K
      • FAG 6303
      • FED 1303
      • MRC 303-S
      • ND 3303
      • New Departure 3303
      • NH 303
      • RIV 4B or 6303
      • SKF 6303
      • STEYR 6303

Lay/output shaft

  • Front of transmission (MG# 92234117):
    • 17 mm ID x 47 mm OD x 14 mm thick - this is a cylindrical roller bearing
      • FAG N 303
      • FAG NF 303
      • FAG NJ 303
      • FAG NU 303
      • FAG NUP 303
      • HOFF R 317
      • HOFF R 317 E
      • HOFF R 317 L
      • HOFF R 317 P
      • Hyatt A 1303 TS
      • IKO A 1303 TS
      • RIV FN 303
      • SKF N 303
      • SKF NF 303
      • SKF NJ 303
      • SKF NU 303
      • SKF NUP 303
      • STEYR N 303
      • STEYR NF 303
      • STEYR NJ 303
      • STEYR NU 303
      • STEYR NUP 303
  • Rear of transmission (MG# 92218424):
    • 25 mm ID x 52 mm OD x 20.6 mm thick - this is a double row ball bearing
      • FAG 3205
      • FED 5205
      • ND 5205
      • New Departure 5205
      • RIV 3205 or 2AANOn25
      • SKF 5205
      • SKF (Eur.) 3205
      • STEYR 3205

Transmission bearing cross-references - I-Convert

Updated: 2008 Mar 10

Throw out bearing

The physical dimensions of the throw out bearing (MG# 92204217) is as follows:

  • ID: 17 mm
  • OD: 40 mm
  • Width: 12 mm

Here are various cross-references:

  • FAF 203PP
  • FAG 6203.2RSR
  • FED 1203RR
  • MRC 203-SZZ
  • ND Z99503
  • NH 203KK
  • RIV ALN 17
  • SKF 6203-2RS1
  • STEYR 6203.2RS

Clutch assembly bearing

The physical dimensions of the bearing used in the clutch assembly (MG# 92201220) is as follows:

  • ID: 20 mm
  • OD: 47 mm
  • Width: 14 mm

Here are various cross-references:

  • FAF 204K
  • FAG 6204
  • FED 1204
  • MRC 204-S
  • ND 3204
  • NH 204
  • RIV 1A 20
  • SKF 6204
  • STEYR 6204

Input shaft (clutch shaft) bearing - front

The physical dimensions of the front bearing on the input shaft (clutch shaft) (MG# 92218421) is as follows:

  • ID: 20 mm
  • OD: 47 mm
  • Width: 20.6 mm

Here are various cross-references:

  • FAG 3204
  • FED 5204
  • RIV 2 AANOn20
  • SKF 3204
  • STEYR 3204

Input shaft (clutch shaft) bearing - rear

The physical dimensions of the rear bearing on the input shaft (clutch shaft) (MG# 92256218) is as follows:

  • ID: 17 mm
  • OD: 35 mm
  • Width: 15 mm

Here are various cross-references:

  • Durkopp 10-2762
  • RIV NAS 17
  • Torrington 10-2762
  • Timken 10-2762

Main shaft bearing - front

The physical dimensions of the front bearing on the main shaft (MG# 92201420) is as follows:

  • ID: 20 mm
  • OD: 52 mm
  • Width: 15 mm

Here are various cross-references:

  • FAF 304K
  • FAG 6304
  • FED 1304
  • MRC 304-S
  • ND 3304
  • NH 304
  • RIV 5B
  • SKF 6304
  • STEYR 6304

Main shaft bearing - rear

The physical dimensions of the rear bearing on the main shaft (MG# 92256218) is as follows:

  • ID: 17 mm
  • OD: 35 mm
  • Width: 15 mm

Here are various cross-references:

  • Durkopp 10-2762
  • RIV NAS 17
  • Torrington 10-2762
  • Timken 10-2762

Output shaft (layshaft) bearing - front

The physical dimensions of the front bearing on the output shaft (layshaft) (MG# 92201420) is as follows:

  • ID: 20 mm
  • OD: 52 mm
  • Width: 15 mm

Here are various cross-references:

  • FAF 304K
  • FAG 6304
  • FED 1304
  • MRC 304-S
  • ND 3304
  • NH 304
  • RIV 5B
  • SKF 6304
  • STEYR 6304

Output shaft (layshaft) bearing - rear

The physical dimensions of the rear bearing on the output shaft (layshaft) (MG# 92201425) is as follows:

  • ID: 25 mm
  • OD: 62 mm
  • Width: 17 mm

Here are various cross-references:

  • FAF 305K
  • FAG 6305
  • FED 1305
  • MRC 305-S
  • ND 3305
  • NH 305
  • RIV 6B
  • SKF 6305
  • STEYR 6305

U-joint carrier bearing cross-references

Updated: 2008 Mar 03

The physical dimensions of the sealed carrier bearing (MG# 92204230) are as follows:

  • ID: 30 mm
  • OD: 62 mm
  • Width: 16 mm

Here are various cross-references:

  • FAF 206PP
  • FAG 6206.2RSR
  • FED 1206RR
  • MRC 206-SZZ
  • ND Z99506
  • NH 206KK
  • RIV ALN 30
  • SKF 6206-2RS1
  • STEYR 6206.2RS

Wheel bearing cross-references

Updated: 2008 Mar 06

I-Convert mag wheels - Front

The physical dimensions of the front wheel bearings (sealed on both sides) are as follows:

  • ID: 20 mm
  • OD: 42 mm
  • Width: 12 mm

Here are several cross-references:

  • FAF 9104PP
  • FAG 6004.2RSR
  • MRC 104-KSZZ
  • ND 993L04
  • NH 6104KK
  • RIV 10L20
  • SKF 6004.2RS1
  • STEYR 6004.2RS

I-Convert mag wheels - Rear

The physical dimensions of the rear wheel bearings (sealed on both sides) are as follows:

  • ID: 20 mm
  • OD: 47 mm
  • Width: 14 mm

Here are several cross-references:

  • FAF 204PP
  • FAG 6204.2RSR
  • FED 1204RR
  • MRC 204-SZZ
  • ND Z99504
  • NH 204NN
  • RIV ALN 20
  • SKF 6204-2RS1
  • STEYR 6204.2RS

Wiring diagrams (very large and easy to read)

Updated: 2009 Mar 28

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.

Download Name and LinkFile SizeNumber of Pages in File
1,389 KB8 pages

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Workshop manuals

Updated: 2009 Dec 04

Download Name and LinkFile SizeNumber of Pages in File
16,942 KB135 pages
2,747 KB23 pages
19,318 KB154 pages
21,349 KB191 pages
  • V1000 Convert [English]
    Thanks to Kiwi Dave and Mike Tiberio for initial scanning and assembly of this document. I cleaned it up some more.
10,960 KB94 pages
23,014 KB147 pages
25,856 KB147 pages
14,651 KB57 pages
3,967 KB27 pages

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

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.