Help Quick

[Honda400exrox]

my friend has a 2001 400EX and its running rich and he doesnt know what to do with it and neither do I, it has a k&n filter and a rev box so would he need a jet kit? or what would he have to do to make it run leaner?

[nosliw]

jet it lower. look at the main jet, see what number is on it, and go the next jet down. also put the eclip on the needle up one notch and see if that helps. might want to screw in the fuel screw just a lil