jetting question

[ktMan]

my lil cousin bought a 01 300 ex and put an aftermarket pipe on it, not sure what kind but it turned blue from the heat. Does he have to re jet the quad? i said that he should put an aftermarket air filter and a jet kit. what do yous think?

[04hmf400]

Sounds as if the bike is running lean. Go up on the main jet and move the clip on the needle down one.