cant400exbeatit
05-17-2009, 03:51 PM
hi guys. i have a 2008 450R with a motoworks SR-4 slip-on, sparks filter kit, and removed or modified airbox lid. i put in a 165 main jet, 45 pilot jet, and clip is set at 5 positions from the top on a NCY-Q needle. it starts up ok and throttle response seems good, but when i'm just riding around and holding it at a constant 1/4 throttle it sputters alot. did a plug check and the plug was dirty black. so i know it's running rich, my question is what kind of adjustment do u guys think i should make? smaller main jet? raise the needle up some? air/fuel screw? pilot? thank for the help.