Motobecane will not run w/out choke

I have cleaned the tank, the carb. I have put on a new fuel tap with in-line filter.

It kicks over and has great spark but will only run if i choke & gas,choke & gas.

Any ideas will help.

I was thinking points or timing but am lacking the tools to take off the stator cover.

thanks

Little Black Bob

Re: Motobecane will not run w/out choke

Pull out the main jet and make sure it's clear. THis is how they act when the main jet is plugged.

Re: Motobecane will not run w/out choke

☂Bob Hansen✄ /
bob OP

Thats the first thing i checked & i have cleaned it out like 3 times.

any other ideas?

Bob

Re: Motobecane will not run w/out choke

Here is what I found with my 50V; Same symptoms, it happened all of a sudden after running awsome for a few hundred miles, I checked and cleaned out the fuel system with no positive results also, so I took the bike to work and we have the cool smoke machine that we use to find leaks in evaporative recovery systems in cars, trucks, etc. I stuck the smoke maker into the moby exhaust and found what may be the problem, a leaking crankshaft seal behind the variator. I ordered a couple from Handy Bikes and when they arrive I'll see if that fixes it.

Re: Motobecane will not run w/out choke

It sounds to me like fuel blockage, or an airleak.

The way the crab mounts to the intake is a little wonky sometimes. Do you have a plastic mounting gasket where the carb mounts? (some models do) Is it messed up?

Are you sure the carb is pushed all the way on the intake?

It does not sound like timing to me.

How is your compression?

Re: Motobecane will not run w/out choke

☂Bob Hansen✄ /
bob OP

Compression is great & i have all the appropriate seals i think day tripper may be on to something. im interested to find out the results.

L.B.B.

Re: Motobecane will not run w/out choke

Bad crank seals can certainly cause this..

Re: Motobecane will not run w/out choke

Ok, I got the seals from Handybikes and spent the better part of the day tearing the motor down and replacing the one by the variator. I did inspect the other one and it was OK. I didn't want to risk damaging the bearing so I left the mag side seal alone. I can say that this was not an easy job by any means. I was surprised at how deteriated the old seal was. I had several of the special tools to do this job and it was still a bear. The bearing was stuck pretty hard in the case and i was afraid I would damage it getting it out. I was able to use a blind hold bearing puller and heat the case just enough to get the bearing out. By cooling the bearing and heating the case installation was a breeze. I didn't get a chance to do a road test because it was raining but the motor started and runs fine. I feel confident that the bad seal was the problem. DT

« 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