I've used Dynojet kits in other bikes, and have always gotten much better throttle response from their needles. I just bought one for my '01 400 4x4 Cat, and it was equally impressive. Directions were spot on - fuel/air mixture is much better throughout the rev range, with better low end grunt. Well worth the $50 to me.

 

is their a web site for this company?

 

http://dynamic.dynojet.com/cfml/Jetk...arcticjets.cfm

Here's their site. You can buy the kits from them direct, or order from Dennis Kirk for a couple bucks cheaper. On this site, you can view the instructions for your model.