07-09 YAMAHA YZ450F: FMF Megabomb Header - Stainless Steel (10) The science behind the MegaBomb header may be FMF's greatest engineering accomplishment to date. You can bolt on a MegaBomb for as much as a 3 horsepower boost, plus the MegaBomb actually reduces noise levels by as much as 1.5dB. The FMF MegaBomb header is yet another testament to the continued dedication of FMF to developing the best performing motorcycle exhaust components. Used by Factory Teams, the MegaBomb is the next level technology you can have today. Produces long header torque and short header over-rev.