I changed carb only, if you use idle-3/4 throttle it is great, but past 3/4 and it will act very rich and foul plug if you stay in it, yes I inspected carb, all passages and jets are un plugged, the carb is new, so I believe it to be ok, my thinking is, can I be pulling the slide so far that it is allowing the main jet to flood the engine, should the needle not come all the way out of the nozzle? It runs geat and the plug is a little dark and wet, so I know I can lean it a little. Hoping someone has had this problem before and knows the fix. Bike is totally stock, just went to a 38 carb is the only mod, oh it does this with airbox lid on and off, but I ride with it on, double air inlet tubes done also. Jetting 180 main, 48 pilot. Thanks!