[mikecoxon90]

i think i got carb issue ok i just got 400ex i put new 440 big bore kit new carb a different cdi and coil new timing chain it has header and pipe and i think stage 2 cam it has a #2 on it im running 165 main and a 42 piolet air screw out 2 turns it starts hard and it spits and pops at top end but plug looks ok when i put the 9 ngk spark plug and i live in fl so my elevation low any one have any idea

 

[Eric the red]

Do you have the air box lid on it?
That makes a big difference jetting wise. If you have the lid on the air box, you're close to what I ran in mine. If I took the lid off it needed a 175 main.