0976 Motobecane Mobylette engine problem

I managed to get the Motobecane Mobylette running and went for a spin. It ran great. I failed to mention I mixed the furl per a sticker on the fuel tank. It said 3ozs of oil for .6gal of fuel. I went a little rich because it had not run in a while and wanted to be sure not to harm it. I went for a spin and shut it off normally. I went to restart and the motor would not turn over when peddeling. I put a 3/8' extension on the flywheel and tried to turn it over. It moved, but with a little hesitation. I have difficulty spinning it over smoothly with my hand with the plug out and the decompression engaged. I hope I did not fuse the connecting rod to the crankshaft. I see the piston going up and down, but the minor sticking confuses me. Unfortunatly I am un abable to start it currently cuz the pedal fell off and the threads are buggered up. Does anyone know what I should expect or look for? Is it possible the engagement clutch is failing. Or do I assume motor. I have never had any of these apart so I am just doing the forum thing til I break it down. Does anyone know where I can get parts? How bout where I find the motor ID numbers. Thanx for all your help and responses.

Paul

Re: 0976 Motobecane Mobylette engine problem

Paul Foytho /

Sorry all I meant 1976 Motobecane Mobylette.

Paul

Re: 0976 Motobecane Mobylette engine problem

Paul Foytho /

How do I remove the clutch. Could the clutch be hung up? I did not grease anything. Paul

Re: 0976 Motobecane Mobylette engine problem

This

http://www.mopedarmy.com/resources/articles/fredsguide/

has a lot of great information in it, try that...

Specifically I dont have any experience with two strokes yet so I cant answer your question directly...

Re: 0976 Motobecane Mobylette engine problem

Paul: There is some resistance from the magnets in the flywheel--they are used to generate the spark, and they make turning the engine over by hand a little tough. It would hesitate at one point and then move more freely, then hesitat, etc. If that's what you're experiencing, it's normal--you may just be having problems starting the moped due to one of the following reasons:

Belt is loose

Clutch pads are worn (when brakes and clutches warm up they tend not to grip as well, too)

I would suspect the belt first. Also, you can start the moped without pedals by pushing it quickly until the clutch engages. Also known as a "bump start". Be warned about riding with one pedal: it will hang down on one side, and when you turn that way, it will scrape the ground. Bad news for stability!

Re: 0976 Motobecane Mobylette engine problem

Paul Foytho /

I understand the magnetic resistance, thank you. However I feel a metal to metal feeling when spinning the flywheel. Does anyone know how to remove the clutch assembly without special tools? Should I remove the zerk fitting and try a puller on it? I would like to see how the motor spins with the clutch off. The belt is plenty tight, I think. It spins the pulley but the clutch does not engage to spin the motor. I am just a little weary of losing a motor on the first run it has had in 15 years. Help!

Paul

Re: 0976 Motobecane Mobylette engine problem

To my knowledge, you need to have a clutch puller to get that thing off an MBK. I can't think of why a freely spinning motor would get stuck like that when you used plenty of oil...I suppose it's possible your crank bearings are worn--that happened to my Puch 2 speed. Everything was fine, then it started whining really loud. It had been sitting for many years.

You could try starting the moped with a drill using a square socket attachment, if you have one. Just take off the magneto cover and stick the square socket into the flywheel, spin the drill and it will turn the engine over. Dunno if that will help you diagnose the problem though.

Re: 0976 Motobecane Mobylette engine problem

Paul Foytho /

I ordered a clutch puller tool and will start there. I find it hard to believe the motor is gone after 5 minutes of running. Especially when I richened the mix. I understand 40:1 is the proper ratio. Has anyone heard of the connecting rod fusing to the crankshaft due to excessive heat. I worked on small engines a long portion of my working career, and it was common on most 2 stroke engines. But only when there was a lean burn condition. Help!

Paul

Re: 0976 Motobecane Mobylette engine problem

Interested in a Motobecane engine? M13 #3410153 ?

Seymour, Indiana

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Re: 0976 Motobecane Mobylette engine problem

what do you want for that motor?

Re: 0976 Motobecane Mobylette engine problem

For starters, a good fuel ratio for motobecanes is 2.5oz of sythetic oil to 1 gallon of gas, not 3oz to .6 gallons. I find it hard to beleive you could have seized your engine with this much oil in it.

If your clutch making it hard for the engine to turn, you'll probably notice that it is always engaged. If not, it may be something else.

I would pull the magneto off first, because its easier and see if thats your problem. Also try spining it with the belt off. You may have seized your pedal crank bearings, but i don't think you did.

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