In loving memory of John
gregory bender

Moto Guzzi Round Head Tonti Frames

Jens Lyck's Guzzitech.dk website archive is now hosted on This Old Tractor

Jens no longer owns a Moto Guzzi and has turned his attention toward his new motorcycle. Rather than let his wonderful online resource fade into oblivion, he has asked me to host his content (both the Danish and English versions). I am proud to do so. I have referenced his excellent compilation for years doing my own work and will continue to do so.

Please update your URLs:
http://www.guzzitech.dk/ is now http://www.thisoldtractor.com/guzzitech.dk/
http://www.guzzitech.dk/english/index.htm is now http://www.thisoldtractor.com/guzzitech.dk/english/index.htm

Other Moto Guzzi resources hosted on This Old Tractor

Carl Allison's wiring diagrams

Guzzitech.dk website archive - courtesy of Jens Lyck

Moto Guzzi Technical Training Videos

Topica Loopframe_Guzzi news group archive

Antietam Classic Cycle - Excellent service spanning tune-ups to restorations

Decals from John Prusnek - Very nicely produced decals you'll be proud to adhere

Relays from Dan Prunuske - Great product, great prices

MG Cycle - New Parts & Accessories for Moto Guzzis

Moto Guzzi Classics - Used and New Parts for Moto Guzzis plus excellent service

Stainless Cycle - Conveniently assembled and polished stainless fastener kits

Steering Damper Kit from Joe Jump

Zydeco Racing - Top notch transmission & rear drive service at unbelievable pricing

Featured sections

Purpose, disclaimer, and other resources

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

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

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

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

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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.

Crush washers

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:

Funcational 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 equiped 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:

Funcational 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 oulet fitting to oil cooler

bottom fitting on right side of transmission

MG# 1200640012 mm1

Dash indicator light improvement

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 nite 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

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

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

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

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

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

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

I-Convert early prototype

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.


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

I-Convert replacment oil lines

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 hydrualic pump is under suction. Be sure to use a thick-walled hose in this application to prevent it from collapsing.

I-Convert transmission O-ring sizes

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

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.

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Overview photos: A view of the rear of the transmission.Overview photos: A view of the rear of the transmission.

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

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Overview photos: Here is the vent. I never did remove this from the case. Just cleaned it thoroughly in place.Overview photos: Here is the vent. I never did remove this from the case. Just cleaned it thoroughly in place.

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

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I began disassembly with removing the converter cover from the 2 speed gear box. I didn't know how critical the position of the bronze bushing was. So I took several shots from different angles.I began disassembly with removing the converter cover from the 2 speed gear box. I didn't know how critical the position of the bronze bushing was. So I took several shots from different angles.

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Another photo of the bronze bushing.Another photo of the bronze bushing.

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Another photo of the bronze bushing.Another photo of the bronze bushing.

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Another photo of the bronze bushing.Another photo of the bronze bushing.

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Another photo of the bronze bushing.Another photo of the bronze bushing.

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Finally I felt confident enough to remove the bronze bushing from the shaft.Finally I felt confident enough to remove the bronze bushing from the shaft.

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

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This is the clutch input hub that interfaces with the clutch plates.This is the clutch input hub that interfaces with the clutch plates.

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Rotate the clutch input hub until the bolts are visible through the access holes.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 outer piece should slide right off.Remove each of the 5 bolts and withdraw the assembly. The outer piece should slide right off.

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Note the o-ring and the holes that must align with the passageways in the previous photo during assembly. You can see that I've already started to separate the two pieces that are held together by the 5 bolts.Note the o-ring and the holes that must align with the passageways in the previous photo during assembly. You can see that I've already started to separate the two pieces that are held together by the 5 bolts.

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Another view of the same.Another view of the same.

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Another view of the same.Another view of the same.

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With the two pieces separated, you can completely remove the front piece, exposing the bearing. I think there was also a snap ring and an o-ring around the shaft, but I failed to take a photo of them.With the two pieces separated, you can completely remove the front piece, exposing the bearing. I think there was also a snap ring and an o-ring around the shaft, but I failed to take a photo of them.

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Remove the bearing.Remove the bearing.

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Remove the seal, note the direction that it must be installed.Remove the seal, note the direction that it must be installed.

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Remove the bottom plate.Remove the bottom plate.

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Here is the seal and several of the passwages.Here is the seal and several of the passwages.

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Drive the seal out.Drive the seal out.

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Here is how it must be positioned during assembly.Here is how it must be positioned during assembly.

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A view of the converter cover.A view of the converter cover.

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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. That about covers the removal and disassembly of the convert 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. That about covers the removal and disassembly of the convert cover.

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

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Another view of the cluthc plates.Another view of the cluthc plates.

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

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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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Another view of the same.Another view of the same.

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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 thoroughout cleaning and reassembly. I probably shouldn't matter, but when resuing 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 thoroughout cleaning and reassembly. I probably shouldn't matter, but when resuing 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 came out easily.The throw out bearing came out easily.

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Another view of the throw out bearing being removed.Another view of the throw out bearing being removed.

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This is the special insert that fits inside the throw out bearing.This is the special insert that fits inside the throw out bearing.

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Remove the pressure plate. Note the 6 springs and the thin washers. The washer fit on the pressure plate, not in the basket.Remove the pressure plate. Note the 6 springs and the thin washers. The washer fit on 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.Note the seal.

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And the o-ring.And the o-ring.

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Before we remove the seal or o-ring, however, lets disassemble the gear box. Start be removing the speedometer drive gear.Before we remove the seal or o-ring, however, lets disassemble the gear box. Start be 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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Remove the cover from the case.Remove the cover from the case.

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Now set the transmission up on end and turn your attention to the output shaft.Now set the transmission up on end and turn your attention to the output shaft.

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Remove the snap ring.Remove the snap ring.

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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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I-Convert transmission seals

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

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

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

Key blanks are avaiable 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

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

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

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 professsional grade, but it is inexpensive and gets the job done for the hobbiest)
    Waldom part number HT-1919 (Waldom is one distributor of Molex products)
    Fry's part number: 1651588
  • 1 circuit connector with receptical and plug
    Waldom part number 1619PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651245
  • 2 circuit connector with receptical and plug
    Waldom part number 1545PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651278
  • 3 circuit connector with receptical and plug
    Waldom part number 1396PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651304
  • 4 circuit connector with receptical and plug
    Waldom part number 1490PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651315
  • 5 circuit connector with receptical and plug
    Waldom part number 1653PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651337
  • 6 circuit connector with receptical and plug
    Waldom part number 1261PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651359
  • 9 circuit connector with receptical and plug
    Waldom part number 1292PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651360
  • 12 circuit connector with receptical and plug
    Waldom part number 1360PRT (Waldom is one distributor of Molex products)
    Fry's part number: 1651371
  • 15 circuit connector with receptical 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 receptical 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 receptical 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 receptical nor plug)
    Waldom part number 1433-34 (Waldom is one distributor of Molex products)
    Fry's part number: 1651555

Oil pump bearing cross-references

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

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 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.

Rear drive O-ring size

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

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

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

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 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.

Steering head bearing cross-references

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

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

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

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

All are of the standard ball bearing type except where otherwise noted; 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 17 mm OD x 14 mm thick
      • 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 NF 303
      • HOFF R 317 L
      • RIV FN 303
      • SKF (Eur.) NF 303
      • STEYR NF 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

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

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

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 serveral 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 serveral 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)

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

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

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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.