Motobecane Carbureator Help!!!

Ray Sanders /

Does anyone out there have any expertise in regards to a carb on Motobecane Moped?

I resurrected a 78' Motobecane Mobylette 50V and it used to only run with the choke on. I pulled apart the carb and soaked it in carb cleaner, and cleaned it very well.

Now, I can't seem to remember which direction the carb float goes (needle end up, or needle end down)

Are there any carb rebuild instructions anywhere? Also, the brass plug underneath the fuel jet seems to leak badly, dripping fuel all over the muffler. It never had a gasket or "o" ring on it before, and never leaked until now.

Please help!!!!! The bike took off like a rocket when I tried to start it, so I know once it's all taken care of it should run well. I'd really hate to junk it.

Thanks in advance!

Re: Motobecane Carbureator Help!!!

XBrandon EdgeX /

First off, if it's only a carb problem, don't even THINK about junking it!

They have a kind of crude exploded diagram of a couple types of motobecane carbs there. Unless a motobecane's carb design is radically different from other carbs, I would say that the needle points up and goes into a little port in the body of the carburator. I'm looking at the diagram right now, and it appears to be a lot different to the carbs I'm used to seeing.

try an o ring on the plug under the jet or just make sure it's tight.

Re: Motobecane Carburator Help!!!

Ray Sanders /

Looking at that diagram right now, Thanks!

I E-mailed Simon as well, as his is only two years newer than mine.

Looking at his bike, I'm glad he was able to recover it from being stolen.

I tell you what, once I get this thing running, I'd feel very sorry for anyone who I catch trying to steal it. Purely from the standpoint of how much work I've put in it.

I put an "o" ring on the brass plug, and now I have to figure out which way the float goes. The diagram seems to indicate pointy end up.

I'm going to try pulling the muffler, and cleaning it out next. I'm sure Simon may have a few tips.


Re: Motobecane Carburator Help!!!

Pointy end up is normal... but I will admit I've never done a MB carb.


Ray Sanders /


Thank You!!!!!

The bike runs the best it probably has in about 15 years!!!! I looked at that expoded view of the carb, and tightened up the brass collar that holds the fuel jet in place, then the brass plug tightened up and didn't leak, even without the "o" ring I tried using.

Now, I have to find a speedometer cable and a choke cable, seems to have them cheap.

Re: Fixed!!!!!

XBrandon EdgeX /

Glad I could help.

I get all my parts at moped junkyard. Their ordering is simple, their prices are fair, and their shipping is WAY FAST! It's never taken more than a week to get stuff from them.

Re: Fixed!!!!!

Hi,Brandon and Ray! That was a perfect example of helping with this forum! I was just going to say that if you'd call B.J. at HANDY BIKES about those parts you might be pleasantly surprised at how much little extra you'd pay for brand new parts.Those aren't parts I'd buy used unless I had to.Call(614-299-0550)and talk to B.J. They shipped quickly to me! BYE!

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