Gordon,

Did you have to rejet when you took theat back fire screen off of the stock filter?

 

Matt, we installed the entire kit on Steve's 1998 Honda 300 4x4. We followed the instructions as best we could until we ran into problems, and then we called Highlifter. They returned our call and answered all of our questions. (How many companies will return your long distance call?)

No, neither of my machines required rejetting after removing the air filter backfire screen. The 450 needed an air screw adjustment, but the 300 did not.

BTW, removing the air filter backfire screen made a noticeable improvement in four Honda 300's on which it was tried, but made no noticeable difference on two others. I have no explanation why. We've only tried it on two 450's, but after a compensating air screw adjustment, both noted a slight but noticeable improvement.

Gordon Banks
Huntsville, AL
2000 Honda XR400R
1999 Honda 450ES 4x4
1997 Honda 300 4x4
1947 Body

 

My buddy ownes a 450s with 27" Mud Bugs, and he is complaning about the power. Thats why I asked. Where is the air screw on the carb of the 450?