stock 400ex putting on a hmf slip on and what should i jet it

[02heavychevy]

i have a completly stock 400ex and i am putting on a slip on Hmf and i am at 600 feet above sea level and i want some ideas of what my jetting needs to be. do i need to change my pilot jet or just the main

[CarGuy7a]

Usually the pipe will come with a sheet and it should have a recommended starting point for jetting.

Me personally I would put in a 155 main. You don't have to change the pilot from stock, but if you go to a 40 pilot jet with about 2 1/2 turns out on the air fuel screw, it will help cold starting. Some say a 42 works better for them but I tried a 42 pilot jet and it was way to rich for my quad.

When I bought my White Brothers E2 pipe they recommended 3 turns out on the air fuel screw with the stock pilot, which did work, but it makes the screw dangerously close to vibrating and falling out of the carb.