New Motobecane Mobylette Owner Needs Advice

Hello! I'm the new proud owner of a 1976 Motobecane Mobylette...and I'm clueless. I've got a few questions, and could use any advice that will help me get started. It does run, but could definitely use a tune-up. I'm going to start today by replacing the spark plug. Here are my questions:

1) How do I tell what kind of Motobecane I have? 50, 50L, etc.

2) Under the photos section I've noticed separate categories for Motobecane AND Mobylettes. Why is this? Were they different companies?

3) The switch near the pedal (ON/Off/Reserve) broke off last night while I was joy riding. Where can I get a good substitute? (It's kind of a pain to use pliers to turn it off and on)

4) Occasionally I've accidently left my moped switched to ON or Reserve. When I do, all the fuel leaks out. Why is this?

5) My moped is very difficult to start. It requires a lot of pedaling, and it helps if you're going down hill. What's the best (and not too complicated) thing I could do to help remedy this.

I know this is a hell of a post with way to many questions. I'll appreciate any responses. Thanks everyone.

_Moped Army rocks!_

Re: New Motobecane Mobylette Owner Needs Advice

1. Look around on the bike there should be some form of tag of plate with the model and year stamped on it (although sometimes they dont list the model)

2.Im not sure what the deal with motobecane/mobylette but I belive they were divisions of the same company or something like that.

3.A replacement fuel valve can be found here

4. The leaking carburetor might be caused by dirt and corrosion or a problem with the float. Cleaning and inspecting should help although there are other people more qualified to tell you what to look for.

5. Are you using the choke and decompression lever when starting the bike? If so hard starting could have to do with a dirty carburetor.


Re: New Motobecane Mobylette Owner Needs Advice

If the fuel leak is through the carb, (not external, a drip from a hose coupling or similar) the carb leak would likely affect starting.

Extra fuel gets into the engine and fouls the plug. Eventually the extra is expelled by repeated attempts and the engine starts.

A leaking float shut-off valve (float-needle and valve-seat) allows the bowl to fill too high affecting performance everywhere, or even to overflow, and that has to be corrected. Find the cause. A float that doesn't float or isn't able to move freely can do it, as can damaged needle or seat.

Too bad about the lever on the petcock.. they are delicate and stick out, begging to be broken off.. live and learn. I might try to repair it with some sort of soldering or welding, it but it would be a real challenge...

..might be enough room to drill a hole through whatever remains.. and then epoxy a suitable piece of steel rod or a thin bolt into it..

Re: New Motobecane Mobylette Owner Needs Advice

Mike Scouty McScoutington /

go to an autoparts store and get yourself a new belt size "17320" or a 4L320. if your belt is worn out you will have a hard time starting and not reach your full speed potential. as far as the leaking fuel, gurtner carbs are very bad for leaking. you can look and make sure you have a good carb gasket and what not. comb ebay, you may be able to find a gurtner rebuild kit that will have everything you need to make that carb like new.

Re: New Motobecane Mobylette Owner Needs Advice

1) How do I tell what kind of Motobecane I have? 50, 50L, etc.


2) Under the photos section I

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