I've got this little machine that is a bear to start, then has no power. It smokes badly and if I remove the crankcase vent tube, there's a steady stream of compression pulses and blue smoke there too. I called the dealership I bought it from and the mechanic told me that the exhaust valve was probably "tight" and out of adjustment. I youtubed it and adjusted the valves to specs. It helped a little, but still hard to get running and smokes.
Think maybe a vale seat problem?


Thanks

 

Checking compression would let you know... Have you ever cleaned the carb?

 

did u buy this new or used? i would say it probably needs rings.. before you do a compression test make sure valves are adjusted to spec. both exhaust and intake

 

I finally built an ATV lift and got the machine off the ground, so I could work on it.
I pulled the head off and there it was, a freaking blown head gasket.
It had separated at the cam chain passage, so the compression blew down into the crankcase. Hence the steady pulse of fumes out of the exhaust vent. Bought a new one for about five bucks, buttoned it up and it runs great. Whew...

 

I'm having this problem too. My exhaust valve was completely compressed. I set it with a feeler guage to 0.005 and my exhaust smoke like a 2 stroke. What specs did you find for intake n exhaust?

 

I called the place where I bought it and talked to their mechanic. He gave me the .005 tolerance too. I set the valves this time when I had the cyl head on the bench, it was a lot easier to see.

 

Tolerance

 

Okay, so that elminates the smoke issue from a valve adjustment. Mine idles blue smoke all the time I tore into the top end and low and behold the piston rings were really out of spec and the piston it's self was all marked up. I'm buying a new piston and rings the head was fine. Perhaps this is your issue too. If not could be valve seals.

 

I'd truly look at your valve seats see what they look like. It's most Likey gonna be the problem