Garelli rally sl please help

Filipe Goncalves /

Does anybody know the correct size of the woodruff key for the magneto side on a Garelli rally SL 86 ?? I need the exact size because filing/gringing down larger ones isn't working. I have been reading past threads on this, and supposedly you can run it without the woodruff just as long as you really tighten down the flywheel nut?? Thanks

Re: Garelli rally sl please help

lapp your flywheel to the taper, i use some rubbing compound and some hand cleaner w pumice or u can just use lapping compound. just the tight fit will hold the magneto in place.

Re: Garelli rally sl please help

^^^^this will not stop you from fitting a key in the future if you choose to. also, it works just swell!

Re: Garelli rally sl please help

Filipe Goncalves /

Pat thank you for your response, I will definitely try it out!

Re: Garelli rally sl please help

Filipe Goncalves /

Aaron thank you for your response!

Re: Garelli rally sl please help

let us know how it works out.

Re: Garelli rally sl please help

> pat splat Wrote:

> -------------------------------------------------------

> lapp your flywheel to the taper, i use some rubbing compound and some

> hand cleaner w pumice or u can just use lapping compound. just the

> tight fit will hold the magneto in place.

Can you explain this process to me, or point me to a thread on how to? I've heard a lot of lapping on here, but I'm not familiar with it.

I feel I should be

Re: Garelli rally sl please help

> Seth B Wrote:

> -------------------------------------------------------

> > pat splat Wrote:

>

> > -------------------------------------------------------

>

> > lapp your flywheel to the taper, i use some rubbing compound and some

>

> > hand cleaner w pumice or u can just use lapping compound. just the

>

> > tight fit will hold the magneto in place.

>

> Can you explain this process to me, or point me to a thread on how to?

> I've heard a lot of lapping on here, but I'm not familiar with it.

>

> I feel I should be

Pretty simple :

Apply lapping compound to the taper . Then the flywheel goes on and gets hand turned a few in one direction , then the opposite direction as many times . Repeat until surfaces involved are showing smooth and matching . The idea is to create as much friction as possible between the crankshaft taper and the flywheel taper .

Re: Garelli rally sl please help

Thanks PD. Makes sense. Simple enough, but I figured it would be.

It's mopeds

Re: Garelli rally sl please help

Filipe Goncalves /

Is there a video o YouTube showing it? I’m still kind confused how to do it

Re: Garelli rally sl please help

> Filipe Goncalvas Wrote:

> -------------------------------------------------------

> Is there a video o YouTube showing it? I’m still kind confused how to do

> it

What are you confused about ?

Re: Garelli rally sl please help

lapping isn't usually even necessary.

the flywheel is held in place on the crank exclusively by the press fit on the taper. the woodruff key serves only to align it for the purposes of timing. If you have a messy taper or flywheel, lapping just ensures a tighter fit, because it is possible to slip the flywheel. Usually this tkes pretty extreme circumstances though, like seizing the engine. It's also fairly common on sachs because it's super duper fun to skid with coaster brakes but that effectively dead stops the rear wheel and for the fraction of a second before the clutch disengages it's connected all the wat through to the crank and I think that's how you start slipping the flywheel. But even then the wooduff key wont save it. it just destroys the key along with upsetting the timing...

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