flywheel removal on Motobecane 50

I have a 79 Motobecane 50...the engine is not turning and my friend and I can't seem to find anything wrong except the fact that there is no spark.

Put in new spark plug, so that's not the problem. Want to access the points to clean them up, hoping that will get everything running. Took off the outer cover, no problem, but I'm having trouble getting the actual flywheel cover off without the special tool. Tried a regular wrench to no avail.

Has anyone else had this problem? Any solutions short of finding the tool? Just need to get it to stop spinning so we can get enough torque on it.

This moped is new to me and I am new to mopeds and mechanics in general, so any advice would be very much appreciated.


Re: flywheel removal on Motobecane 50

you can stop the spinning of the engine by stuffing rope in the spark plug hole to act as a piston stop, or purchase a craftsman strap wrench and use that to hold onto the flywheel/rotor..

Re: flywheel removal on Motobecane 50

I was a dealer here in Canada (N.B.) and seldom had any trouble with ignition points. the sparkplug cap has a resister built in the same as any other motorcycle or snowmobile and they can easily fail. All you need is a new one. Other problems are the ground wire from the motor to the bolt holding the ignition coil. The wire breaks off easily. Next is the fact that the ignition is weak compared to most other types, so the plug gap is critical, must be about .018" to not over .026". Brand new plugs are NOT gapped properly at the factory for anything except automobiles. Finally, to remove the flywheel, the bikes I sold were 1973 to 1980 should be the same as yours. There was a tool that screwed into the plug hole (about 3" long) and this touched the piston keeping it from moveing. The nut holding the flywheel had a 3/8" square hole and is LEFT HAND THREAD. This only removes the flywheel. Inside is the seperate cam which does not have a key to locate it, is made of cast iron and may split in half if you over tighten it when reassembling. You need a special puller to get it off but then you would have to retime the points to crack open at 1.5 mm to 2 mm BTDC. Check everything else before removing flywheel, even the main ignition coil is a weak point. use a coil from any old dirt bike or four wheeler, I think even a CDI coil should work.

Re: flywheel removal on Motobecane 50

You can purchase a piston stop here:

Screws right into the spark plug hole..

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