FMF Racing Megabomb Stainless Header for Yamaha YZ250F 14-18/YZ250FX/WR250F 15-19FMF MegaBomb Header Yamaha YZ250F YZ250FX WR250F The FMF MegaBomb header is the top choice for many Factory Teams and is best suited for Motocross, Supercross and GNCC style riding where more bottom to low end response is desired. The patented header design allows exhaust gasses to expand, cool and ramp back up at a higher velocity. This results in torque gains typically associated with longer headers, and the healthy over rev of a short header. When