1978 Garelli

I have a 1978 Garelli that I just replaced rubber clutch on. It starts up fine and rear wheel spins normally while bike is on kickstand. As soon as I take off kick stand and give full throttle the bike engines just revs up and does not accelerate/ move unless I’m going down hill of driveway. Does anyone know what can be the cause of this? I also have 400 ml of 30weightND lubrication oil inside. Thanks

Re: 1978 Garelli

Certainly sounds like the clutch is not engaging. I'm no garelli expert, but the manuals may help: https://drive.google.com/drive/u/0/folders/1znPdXCXDGjQ9rRxyAk7CayYSaOss8Gzm

Re: 1978 Garelli

todd amundson /

400 Cc’s is 400 ml but I believe you’re overfilled. Take out 70ML and see what happens

Re: 1978 Garelli

Will do. Thanks for responses

Re: 1978 Garelli

Make sure the main gear is tight.

Re: 1978 Garelli

Is main gear the one in back of clutch?

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Re: 1978 Garelli

> Dave Jenkins wrote:

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

> Is main gear the one in back of clutch?

Yes. Should be a 17mm socket if I remember correctly.

Re: 1978 Garelli

I don't understand why you put a new rubber in. The old one wasn't bad.

Re: 1978 Garelli

Have the cases of the engine ever been split before?

Re: 1978 Garelli

The old one was swoll due to putting wrong oil in. Before I put in new rubber the bike would die when rear brake was engaged. Now with new rubber the bike doesn’t die with brake engaged but it will not accelerate. Could it be the small bushes need to be replaced also? Could they have swelled and are creating new issue?

Re: 1978 Garelli

> Dave Jenkins wrote:

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

> The old one was swoll due to putting wrong oil in. Before I put in new

> rubber the bike would die when rear brake was engaged. Now with new

> rubber the bike doesn’t die with brake engaged but it will not

> accelerate. Could it be the small bushes need to be replaced also? Could

> they have swelled and are creating new issue?

No. Those are vibration dampening and nothing more. The main gear is suspect as Stephen has mentioned more than once. That gear and its shaft are a tapered fit. No splines or keyway to keep it engaged if the nut were to come loose.

Re: 1978 Garelli

Take a picture of the top of the motor where the two engine cases (halts) meet.

Re: 1978 Garelli

Top pic

image.jpg

Re: 1978 Garelli

It is strange indeed. Maybe post a video of the bike running but not accelerating. I have a few garelli bikes but have not had this issue. Especially with a fresh clutch installed.

Re: 1978 Garelli

Will do. Could there be too much room between rubber and housing?

image.jpg

Re: 1978 Garelli

The engine doesn't look like its ever been apart.

Re: 1978 Garelli

I don’t believe it has.

Re: 1978 Garelli

It does look like there is a bit of extra space between the clutch and bell but it should still be able to grab.

Get the oil level corrected and see if that helps at all first.

Unless you see a pool of transmission oil below your bike I would say that you dont have a leak from there that would be the cause of any issues. Have you had a chance to look over the repair manual in the wiki on here? I posted a good one I have had for years on there a while back. One of the best repair manuals I had found for the garelli engines.

Re: 1978 Garelli

I just noticed when I grab this housing there is slight play in it. Should this be 100% stable when pulled side to side. Can screw underneath spring be causing slippage?

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Re: 1978 Garelli

There should not be much play on that since it is connected to your piston crank shaft. Does your magneto have the same play? It is connected to the same shaft.

If there is that much movement then maybe some bearings have gone bad and you need a crank/bearing replacement.

Being that the engine "runs" it seems unlikely that this would be your issue. Crankshaft play would cause larger problems and probably prevent the engine from running at all.

Re: 1978 Garelli

Like Jay said, grab the flywheel and see if you have in and out play there. If you do, you’ve most likely got a major air leak in addition to spun bearings. I’ve seen it a lot on Garelli NOI motors. . (edited)

Re: 1978 Garelli

Flywheel is 100 percent Stable.

Re: 1978 Garelli

You still may have an air leak coming from those 40+ year old crankshaft seals.

Re: 1978 Garelli

Understood. Thanks

Re: 1978 Garelli

Turn the clutch bell with one hand and try to stop the back wheel from turning with the other hand. (edited)

Re: 1978 Garelli

Did you make sure this nut is tight? If so post a pic of you starting the moped and trying to take off on it.

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Re: 1978 Garelli

> Stephen Simmons wrote:

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

> Did you make sure this nut is tight? If so post a pic of you starting

> the moped and trying to take off on it.

He means video not pic.

Also check the nut behind the handle bars.

Re: 1978 Garelli

> live ɘvil wrote:

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

> > Stephen Simmons wrote:

>

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

>

> > Did you make sure this nut is tight? If so post a pic of you starting

>

> > the moped and trying to take off on it.

>

> He means video not pic.

>

> Also check the nut behind the handle bars.

Thank for clearing that up evil!

Re: 1978 Garelli

What’s the chance of this being the culprit. Gears look a little worn. Can this cause slippage?

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Re: 1978 Garelli

> Dave Jenkins wrote:

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

> What’s the chance of this being the culprit. Gears look a little worn.

> Can this cause slippage?

Nope that's normal.

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