superchief 500 vapor locks

[dave phelps]

Ok you 2 strokers I gotta pick your brains a little bit here! what makes these machines either vapor lock or lose spark when they get hot or its hot outside?? I've had 2 machines do this and 1 is a cdi ignition.
Thanks
Dave

[Toys4Me]

My original 2 stroke would run great until it would warm up. My issue was bad rings.

[dave phelps]

My original 2 stroke would run great until it would warm up. My issue was bad rings.

So was your compression low when cold? or how did you diagnose this??
Thanks

[Toys4Me]

Compression was good cold. Found the issue when we pulled the head and you could move the piston. Then came the first predator.

[dirtdobber]

Dave, losing spark could be a symptom of a bad coil. Although I don't know your specific engine, CDI ignitions rely on coils to fire (an exciter coil at the flywheel and then a different coil to produce the spark.....I think). As the temp rises so does resistance, and resistance impacts the voltage output from the coils. If the output from the coil isn't just right it won't fire. Last year I had to replace the coil on my B&S 20 horse. It quit firing when it got hot. New coil fixed the problem.

[dave phelps]

Compression was good cold. Found the issue when we pulled the head and you could move the piston. Then came the first predator.

LOL Thanks Mike!

[dave phelps]

Dave, losing spark could be a symptom of a bad coil. Although I don't know your specific engine, CDI ignitions rely on coils to fire (an exciter coil at the flywheel and then a different coil to produce the spark.....I think). As the temp rises so does resistance, and resistance impacts the voltage output from the coils. If the output from the coil isn't just right it won't fire. Last year I had to replace the coil on my B&S 20 horse. It quit firing when it got hot. New coil fixed the problem.

Ok Thank you! I dont know alot about this ignition stuff for sure!!

[Don]

G50Bs always had a really bad habit of losing fire to one cylinder when they got good and hot. I was told that the problem was that the stator plate warped with heat and one set of points wouldn't open far enough to fire correctly. I'm not sure that was the case but I know that a CDI would solve the problem. Does yours misfire or does it make the low, throaty whaaood whaaood sound? (Yeah, that's what I said.)

[dave phelps]

G50Bs always had a really bad habit of losing fire to one cylinder when they got good and hot. I was told that the problem was that the stator plate warped with heat and one set of points wouldn't open far enough to fire correctly. I'm not sure that was the case but I know that a CDI would solve the problem. Does yours misfire or does it make the low, throaty whaaood whaaood sound? (Yeah, that's what I said.)

Lol Don. It starts losing power and yea. I hit the throttle like to pump it and it will just fall on its face and makes the sound your saying too! Lol.