[Rleslie353]

I have a 400ex I have a full white brothers exhaust I have a 38 pilot and 138 main! What jets should I use and how many turns out does air fuel screw turn out! My bike won't stay running now! I definately need help I am really lost!

 

[Here 2 help]

You are too lean on the main jet - stock is a 148 - with the aftermarket exhaust, you might want to use a 155 or 160 main jet

The fuel screw only adjusts the air to fuel mixture at idle - start at 3 turns out from lightly seated - warm the engine from 3 to 5 minutes and adjust the screw for smoothest idle