ok i got a 05 yz450f with a pro circuit pipe on it . i got for $1200 buck cuz it didnt run. we got it to start using the choke but when we turn the choke off it dies . we tryed adjusting the fuel scerw and changing the main and pilot jet but it didnt work. the main jet that was in there was a 168 the pilot was a 45 the one we have in there now is a 165 main and a 42 pilot . the fuel screw is at 2 turn. really need some help if anyone can thanks.