I was wondering what the stock setting is for a 400ex?
Also turning the air screw in richen or lean it out?

What jets are you running? with which mods?

 

Stock 148 main, 38 pilot, clip in the middle, fuel screw 2 turns out for initial adjustment. I run a 42 pilot to get rid of the cold bloodedness and a 150 main on a stock machine with a slight exhaust mod, plug is tan colored.

 

this is what I am dealing with,
My friend and I put a hotcam stage 2 in his 400ex. He also has a fmf powerbomb pipe, no lid and K&N filter. He was/is runing rich, but he doesnt remember what jets he put in his quad when he piped it.
I thought I would try to find out some info before we tore the carb apart.

Air/fuel screw in or out to richen and lean it?

 

Turning the screw in will lean it out...

 

thanks