Hi guys new to site been checking posts to see if any close to my problem.No luck so far. Problem bike starts fine but sound alittle flat with brake on.Choke on or off doesn't matter.Lift bike on stand release brake engine sounds great revs right up idles down.Take of stand give it throttle will not even pull itself and dies out. Cleaned carb ,boiled carb,Cleaned clutchs ,petcock changed , compression 115 warm any Ideas thanks

 

Welcome to the forums.
Plugged pipe?

 

thanks lt80 I will give that a try will let you know

 

not the pipe blow through it with ease. Must be clutching.anyone know good clutch diagrams thanks

 

Ohio Motorcycle ATV Dealer - North Ridge Yamaha Suzuki - Geneva, OH - Scooter Utility-vehicle, snowmobile
You can look at the parts fiche's there.
You mentioned that the choke on or of don't matter but let's clarify. The choke makes no diffeence in the way the motor runs or it just don't matter for this bog problem?
It's a good idea to service the clutchs anyways.

 

did you actually take the cap off the end of the pipe and look and the spark arrestor? Our 2 stroke did the same thing, bog and thought the pipe was ok. Took off the endcap and the spark arrestor screen was so dirty hardly anything was getting past it. Cleaned it and now full power again.

 

No end cap or a screen on a LT80 BigJon.
You are correct in your thinking. I had a Eton in w/plugged screen.
I "accidentally" burnt a hole or 2 in the screen.