A freind of mine just picked up a 2006 yz450f. The only addition is a fmf powerbomb header. The bike pops alot, and i mean ALOT... Also when you rev it hard it will sometimes shoot a flame out of the exhaust?? Is this a jetting problem?? How good is the jd jet kit?? Will buying one of those allow us to jet his bike correctly??? Thanks very much.