New EX's
 

Picked up a 400 for myself, a 300 for the wife and my buddy got a 400 as well....should be a blast tomorrow [img]i/expressions/face-icon-small-smile.gif[/img]

I put a WB E series slip on, K&N and a 170 jet in mine, his is bone stock....curious to see the power difference....

New EX's
 

The 170 is way to big. Put a 152 or 155 main and also change the pilot to a 42 or 45 to make it start easier. Take the head pipe off and clean up the welds on the inside of the header on the 400 and it will make it run almost like an after makert header, Open up the airbox and it will run alot better also.

New EX's
 

If he has the air box lid removed,and its a K&N jet kit, that is what the jet kit instructions say to put in(170). Check out Exriders.com for more power tips.