Corry,
Good luck at the track. Your jetting will probably work fine. If you do want to increase your power, though, you'll probably have to go to a more free-flowing air filter and a bigger jet.

Let us know how it works out!

Clark

 

The same thing happened to me with my airbox lid. I took it off and saw no difference. Then I increased my main jet size 3 sizes and added a UNI filter, and presto, better throttle response and more horsepower in the mid to top range. So I would suggest giving that a try and see what happens.

 

ATVer14-what jet size are you out now? when I run my 400ex with or with out the lid it doesn't have low end power to pull the front end up in 2nd gear. I figure it is lean because I have a 142 main jet and it get hot fairly quick. I was curious so I can know what to up the jet size to with out an airbox lid. Thanx

 

Your jet size and his are going to be different, due to altitude, I think. I am considering the new filter/modded airbox thing, but my husband will probably kill me if I spend anymore money on my quad right now! [img]i/expressions/face-icon-small-shocked.gif[/img]

 

I went from a 125 stock jet to a 128. I also lowered the needle clip position to the 2nd setting (richer). It seems to be running a little bit too hot still, so next time I'm at my Honda dealer, I'm going to go with a 130 and see how that works out. You've got to remember too that I'm at sea level and we've got different machines, so what's right for mine might not be right your your's.