04 jetting. stock with no airbox

[CR500rider]

ive got an o4 450 with stock pipe but baffle removed and no air box. It likes to die if you dont keep it running after about ten minuets. I took out the 163 main and replaced it with the stock 118. now the engine wants to stall after half throttle. Any help with what i should do?

[blasterfreak99]

i have the same thing done as you and i have a 155 main, 52 pilot, 55 leak jet, and my fuel mixture screw 1 turn out. it is a little rich on the main circuit and a little lean on the needle but that can easily be fixed by getting an adjustable needle and one or two sizes smaller on the main. i am not sure what elevation i am at but im in east tn in the appalachia mountains. hope this helps