You have a sheared flywheel key.

KNOWSALOT

 

I checked the flywheel key,i am wondering about cdi box causing this trouble it ohms out correctly,but i know that does not mean much.

 

We are jumping from carb to ignition. Can you rule out ignition for us by using a can of starter fluid to prove that the ignition is working when the engine is receiving some kind of flammable mixture (this is assuming that it is running lean based on your use of the choke).

See if you can prove that spark is occuring properly at higher rpms. I would be tempted attach a timing light just to see if it cuts out or something.

If you start squirting starter fluid around, make sure you have the appropriate saftey precautions against fire. Did that sound like I had experience with a fire in a quad? Me start a fire? No, never. Maybe just a little fire but I had it under control. Good thing the cat's water was close.

 

I found today by blocking the air jets at the front of the carb,the engine will rev,now should i try jetting richer, or find the cause for needing richer jetting.Carb cleaner flows freely through all jets,manifold is sealing,Can the throttle slide wear enough to cause this.Throw some ideas at me.Thanks