400EX Jetting

[NCexRider]

Alright guys, I sold my '05 and I'm about to pick up an old '01. It needs some jetting and it's like it's alll foreign to me since it's been a while since I dealt with this stuff. Someone refresh my memory please.

What are the stock main and pilot jet sizes on an '01 EX? What size pilot do most people bump up to for easier starting and idling? What main do most run with stock motor, slip on pipe, and no air box lid? I'm located in NC, not real far above sea level. Thanks in advance!!!!!!

[my88r]

a 42 pilot, maybe a 158 main. no air box lid changes the jetting a pretty good bit.:grr:

[STUNTIN400EX]

would running with the lid removed cause it to run rich or lean?

[my88r]

Originally posted by STUNTIN400EX
would running with the lid removed cause it to run rich or lean?

lean

[97WarriorRider]

I just pulled the 155 out of mine and put the 148 in..I bought the carb with the 155 in it and took the 148 out of my other carb..I have all stock motor , stock exhaust and a homemaid airbox lid made outa plexiglass with a few holes in it..How do you check the size of the pilot?