Is this a clutch problem?

Hey all,

Last weekend I aquired a 1978 Jawa Babetta in quite good condition. I've cleaned the carb, gas tank, added an inline fuel filter and new plug. This would be fine and good if I could get the engine to turn over. Last night I took apart the clutch and had a look at the magneto to confirm my suspicion that no matter how hard and fast I pedal the engine is not engaging.. the outer ring that surrounds the clutch will spin but will not spin the clutch therefore not turning over the engine.

I am very new to the world of mopeds and am still a little lost as to what _should_ happen to make the bike start (or atleast turn over). Should the pads in the clutch be atleast tight enough against the ring to turn the engine over with the decompression lever pulled? or is there another mechanism that should be turning the engine on a start that is obviously broken but I havn't found?

Thanks,

~Jeff

Re: Is this a clutch problem?

Screw the spark plug out and stick a screwdriver or somethin in the hole.Now pedal it gently.You should feel if the piston is moving.

Re: Is this a clutch problem?

Thanks for the suggestion but I'm certain that the piston is only moving when I spin the inside of the clutch (or the magneto on the other side) I can feel the compression when I do this. This is also the assembly that controls the points and the magneto which I'm sure must be spining in order for the bike to fire.

thanks again,

~Jeff

Re: Is this a clutch problem?

I'm not sure how your bike is set up,but on a lot of bikes,you have a clutch lever which pushes a friction plate against the clutch hub to engage the engine when you kick it over.THEN the engine rpms do the rest.With my ANKUR though,it's a decompression lever only.It has a disengagement spring which will let you pedal the bike home if you have to.Is your disengagement possibly stuck?I just don't know Jawas.

Re: Is this a clutch problem?

Hey Don,

I figured it might be the same thing (disengagement spring) but I checked and its acutally a switch that disengages the countersprocket and it is working properly.

Thanks for the idea..... keep suggestions coming.. what I'm realy trying to figure out is how the average moped without a friction plate clutch lever engages the crank. Does it just engage due to a stiff centrifugal clutch setup or is there usually another mechanism at play here? If I can't figure it out I think I'm going to figure out some release-albe way of locking the clutch to the ring so it has no choice but to turn over when I kick(pedal) it

thanks again,

~jeff

Re: Is this a clutch problem?

Reeperette /

Check to see if the Circlip that holds the clutch in place on that side is bent or missing.

-Ree

Re: Is this a clutch problem?

Jeff,

I've been "tolerating" this exact same problem with my 1975 Batavus HS-50. The nut that holds the clutch assembly onto the crackshaft is tight but the clutch assembly turns without the engine turning over. It seems the clutch kas a key on it that is worn off. Might yours be having a similar issue? I could get a beautiful spark when I took the plug out and tested it but the engine couldn't turn over once there was compression. I had to manually craft a locking key that would keep the clutch in place. So far it's working.

Richard

Re: Is this a clutch problem?

Sounds like the centrifugal starting shoe set is stuck in the closed possition. You might want to clean the pivot pins for these shoes and apply a drop of oil to the pivot.

Chris

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