New to the forum and really needing help.

I have an 85 yfm 200 4 stroke. I bought it as a basket case project. I have it running but the carb is giving me fits. It will start and run at a high idle for several minutes, then slowly drop until it dies. When it starts to idle down to die I can give it more gas and it will go back up to the high idle unitil it idles down again. If I put it in gear it will die unless I stay on the trottle.

I have rebuilt the carb several times over and made sure there are no air leaks. I dont know what I am missing or what else it could be

I have rebuilt several old ATVs but this one has me stummped. Any help would be greatly apprciated.

 

No ideas?

 

Well I figured it out. The choke was not fully sutting off the extra fuel when I took the choke off. It idles good now, BUT (thers always a big but) now it bogs down while riding, like it's getting too much fuel. Until it dies.

Needle is set in the middle, air screw is at about 2 turns out, and the idle is about 2 1/2 turns out.

Any quesses?

 

I got it idleing good, but it bogs down a when your going slow on the throttle. if you stab it, it goes fine. It boggs bad, and tries to die when going over rough bumpy terrain.

Would the float level cause it to try and die on rough terrain?

 

Pull the choke when it bogs, if it gets better it's a lack of fuel, if it dies it's to much fuel.

 

Ok, i have the same 85 yfm and i can not get this carb tuned in correctly for the life of me! needle is set in the middle, idle is 2 and a half turns out, and i have no clue witch skrew is the air skrew. PLEASE HELP