Engine Run-on
 

Does low grade fuel cause run on? If not, how do I stop it? Its just started happening lately since 2 weeks after the carb rebuild.

I guess you're talking about dieseling, where the engine keeps running after you shut off the ignition? If so, low grade or bad fuel can cause that. I've also heard that if your timing is off, that can be a cause too.

yup....what he said!! lol

Timing is most likely the cause (I think). If you notice it change from fuel to fuel then just stay with the one that works. If not check your timing and adjust accordingly.

Other possible causes:
Idle Speed too high (regular idle speed, not with choke)
Is choke on (check choke settings)
Build up in engine (need internal cleaning) -heard this

A vacuum leak will cause it too. You did say it started after the carb rebuild.

Its totally random though. Its driving me nutz. One time it ran for 35 seconds after I got out!

I've been having the same problem lately. It happens totally randomly, but it hasn't gotten as bad as yours yet. I haven't done any carb. work either, and its not vacuum.:confused:

Also if you're running rich it will do that as well. But also the others mentioned above are also problems.