Hi everyone,
my father has a 1986-1987 trx350 foreman. shortly after he bought it, when started cold the bike motor would rev high untill it came up to temprature.

The bike has sat for a couple months so today we started it and the idle went sky high and will not come down by its self. Also using the coke did not change the sound or how the eninge ran

I removed the carb cleaned the jets and passage ways. reinstalled. same problem. sprayed the rubber peice between the carb and engine, looking for air leaks nothing found. tryed adjusting the idle screw to manual spec

The only thing that makes the idle go down is if you cover the intake side of the carb or air cleaner with a rag. then the idel will come down..

any ideas?

 

does the throttle cable and the slide move freely? The idle mix could be set lean as well, but that usually won't change on it's own. Also make sure the slide is installed correctly, the slot lines up with a pin that will be about 1/2 way down the hole, and the little notch with the bevel sits on the idle adjust screw. if in backward they will sky wrap like you describe.