I just tore down the 400ex I'm adding a 11:1 Wiesco piston stock bore Shaving the head 10 thousandths 5 angle valve job Stage two cam hot cams, heads flowed and exhaust and intake I have a W/B Pipe K&N Lid off What is your suggestion for Jets and please only expericed Builders and riders answer please I ride about sea level about 4500. Run 112 OC gas, any suggestions will I need to mess with idle needle as well as the jets, I ran still a little rich with stock jets with the pipe and K&N at this 4500 sea level. help want to start off with a close match.

 

40 pilot, raise the needle one and start with a 160 or 165, that should get you close enough to aleast break in the cam and piston.

 

that seems like a good start.

i assume you ride at an elevation of about 4500 and not at sea level?

 

yes 4500