Motobecane problems

hey there everyone what's going on? ok my 79 mobylette 50v which had been running great just decided to stop running the other day. it had been raining heavy the night before as well as when i was riding it when it decided to just stop in the midst of riding. at first i thought i just ran out of gas as i've been doing that lately but at the same time thought not because it just abruptly died, not the slow gradual stall that happens with no fuel.

so i've since replaced the spark plug with a new one, cleaned out the carb and cleared the exhaust pipe (ok i just tried to start it with no pipe on at all) and it's still not starting.

i'm thinking it has to be something with the electrical system as when i go to start it afterwards gasoline leaks out the back of the exhaust pipe so it doesn't look like it's getting ignited.

another weird thing is i pulled off the plastic cover off of the magneto and there was some pooled up water in there (my cover is a bit cracked and beat from two moped accidents). it wasn't a crazy amount but it was in there collected and must have been like that for a couple of days since it hasn't rained since.

so, any suggestions? electrical systems in general i just don't understand and they scare me, so, i don't know what i'm doing. if anyone can help at all i'd really appreciate it.

thanks then,


Re: Motobecane problems

Leon Swarmer /

Dave, take the plastic magneto cover off again and give everything under it some quality time with a hair dryer.

water will conduct electricity and send it palces you don't want.

Don't get close enought to melt anything though....if you are lucky you can then spin the engine with the plug out (but grounded) and see a spark. I don't have a moto...can you see the points in there. Are they clean? are they too worn??

wait for other answers, too.


Re: Motobecane problems

With the right tools, opening up a 50v's magneto is a cinch. The bolt is reverse threaded however, so be careful if attempt to remove it. On most bikes you can use a 3/8" socket wrench with no socket on the bolt, and a use a piston stop on a strap wrench to keep the engine from turning. Water is bad for electrics, but it should be alright when it dries out.

i saw this same thing happed to a malaguti once, and i think the water ruined the condensor. Its something you can test, howver, and pretty easily. Motobecane have i think three coils, and underneath the left hand one is a thing about a square inch in size and probably green. This is the condensor. if you take it off and test its resistance, and it reads about 200 ohms, then you're alright. A bad condensor will allow you're bike to spark, but won't run more than 5 minutes or so.

Good luck.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account