No V1 crank shim?


I’m rebuilding a Minarelli V1. It’s the earlier version with the stub plane crankshaft. I think it’s from 1975.

For the life of me I can’t find the magneto side crankshaft shim. At first I thought I dropped it somewhere but I looked all over the place and it’s nowhere to be found. I’m usually pretty anal with motor parts and always place them in order in a tie-wrap. I’m pretty sure that if it had fallen somewhere I would have noticed it. Is it possible that there was no shim from the start?

The crankshaft 6203 bearings were FUBAR rusty and the traces on the crank match the bearing inner races on both side.

I measured both the old and new crank with a digital calliper and they both measure the same, +/- 0.1 mm (the new one measuring less, IIRC). How much tolerance is acceptable in a V1? And how to I tell if the cranked needs to be shimmed once the case is closed?

Thanks for your help!

Re: No V1 crank shim?

isnt there a diagram?

Re: No V1 crank shim?

Guillaume Guite /

Yes there is, and there is none on the diagram. But on the wiki it says "There's a crank shim that ALWAYS lives on the magneto side of the crank. The v1 service manual does not show this shim in the exploded diagram, but it's there. Some engines even have two of those lil' buggers! Whoa! In case you lost yours, McMaster-Carr can help you. The size of this shim is 18mm ID x 24mm OD x .6mm Thick. You might have to double up two .3mm thick shims to get yer .6mm "

Rebuilding a Minarelli V1

Re: No V1 crank shim?

Ive Never had a crank walk in between the bearings before.

Re: No V1 crank shim?

MInarelli manual says there is a shim. Page 28 and it's also mentioned earlier in disassembly of engine.

Re: No V1 crank shim?

Guillaume Guite /

OK thanks.

Goddamnit. Where the hell have you gone, you little fucker!

How critical is the inner diameter? Treats has Vespa shims that are 20mm ID instead of 18.

Re: No V1 crank shim?

Nope! get the right size. Loose shim is worse than no shim.

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