model 125k02....starts, runs fine.. turn it off and then try to start it. It tries to start, tries to idle up, but acts as if it is deiseling, tries to idle up and backfires thru the exhaust for approx 20 seconds or so, then dies..... cools off and runs great...already built carb...is the coil breaking down, or, stuck valve...help..help, help me if ya can.......:

 

Does this one have the automatic choke?

 

no choke, uses primer bulb..i swapped carbs with same effect.

 

this must be a new symptom, i know i have never ran across it before....someone told me to check the crossover vent tube.. does that make sense???

 

I don't know what part he is referring to as a "crossover vent tube". Did you try a new plug? New air filter? If neither helps, it could be a coil problem as well.

 

Thanks cheese, kinda thinking it was a coil issue, the crossover tube is the vent tube from the carb that goes across the top of engine to the valve cover on the other side of the engine. b-s calls it a breather tube...:

 

what would be the symptons of a coil going sour???? could i have a stuck or bent exhaust valve??

 

Usually a coil shuts the engine off when it gets hot and will not allow re-start until it cools.

The breather hose is not related to the problem.

A valve problem is possible, but not so likely. Does it lose compression when this happens?

 

Thanks cheese, i'll have to check compression..started it yesterday and it ran like a champ,,,,shut it off, and started just fine for an hour or more...

 

Does sound like a coil going bad. It could also be a clogged vent in the gas cap.