zirri short 4th

Is the replacement zirri gear cluster a straight swap or do modifications need to be made in any way

…one from PX because with one of this you have the same distance that with 3 from special… [H]

I presume you are talking about the gearbox „shim“ thats sits under the circlip on the end of the layshaft after the 4th gear drive cog (apologies if this stretches your english too much)

I assume you are referring to the main drive gear spacing, which minmises play.

I currently have a t5 shim already fitted.

…had a look at S.I.P catalogue.
The article you need should be:
Spacer gearing
art.-n : 13839300


cheers for the rapid response Curare. I’m finally building another engine to suit that zirri pipe that the polini 130 was too tame for.


yes, just check all the assembly is well in place with no play.[:smokin:]

…if you can have some minor modification to your cylinder and piston since I know you are aiming high.
You could send them to worb5.[H]


it is not a straight swap. For question of distance.
You have to use euther 3 vespa special thrust washer ( I don’t know if it is the right english term, but I am talking about the ring for distance), or more elegantly put one from the PX.
The important thing is that all the gear assembly is well in place after the assembly.
… hope it is clear…