need help?

[kfxriderirv]

i have a friend that has a 99' 400ex its so slow it has a white bro's slip on an k&n filter and sprockets and we dont know why its so slow plez. help

[sled_ed 300ex]

theres a fith gear and if not check the jetting maybe it just does not have enough power do get it reving hi enough

[MXridin841]

sell it then get a z400. lol. then it will be fast.