I have a 400Ex with 6 vent holes,FMF powercore IV2. I live in Ohio. I was still running a little lean with the 155 jet. They didnt have a 158 so I put in a 160. Do you think that will be to high of a jump, for the MODs that I have.

 

no that should be about right.

 

not that big at all, I used to jump 10 digits when pipeing my 2 strokes

 

6 holes
lrd full exaust system.
170-main
45-pilot
dyno needle-3rd notch.

You can push it more if your exaust really flows.

 

10 to 15 is normal for Kiehin carbs, 20 to 30 is normal for Mikuni.

 

i am running a 165 main and i live in vegas...