Hi,

1999 400ex--White Bros E-series--K&N filter sys--Performance Chip--no airbox lid. What Jetting is a good place to start?
I made the mods for my Pal, who owns it, but need some Jetting advice. Currently stock Jetting but havent run it.

Thanx,
Plad

 

157

 

look in my signature i would go with a 155 and go down one if needed

 

Depends on your elevation. If your near sea level, 165-170 main, needle clip on 3rd position, and 3 turns out on the pilot screw should be real close. That is what dyno jet recomends with their kit. It works good for me.

 

Do what 400EXTC suggests but go up on the pilot, 45, or 48.