Big Gun Exhaust EVO Race Headers for 2004 13 Yamaha YFZ450 09 24601 MPN_27 1057 (2) 18mm to 12mm O2 (2) 18mm to 12mm O2 adapters Product Details Tire Diameter Speed Rating Load Rating Wall Construction Tire Tube Type Rim Size Product Line Wiseco Bottom End Gasket Kit Part Number WB1170 Fitment Type Unit Sale Qty Each Style Material Color Size Finish Position Functional Length Cable Sleeve Length Cable Sleeve Travel Driver Seat Length Passenger Seat Length Driver Seat Width Passenger Seat Width Piston Cylinder Size Piston Size Added Cylinder Stroke Volume Final Engine Displacement Exhaust Configuration Muffler Size Muffler End Tip Style Windshield Height Windshield Width Handlebar Diameter Ca ARB Compliance Non CARB Complaint CARB Compliant Product Disclaimer Product Details Product Line Big Gun Exhaust EVO Race Series Part Number 09 24601 Fitment Type Model Specifc Fitment Use Type Unit Sale Qty Each Style Size Position Material Stainless Steel Color Finish Exhaust Configuration 1 into 1 Header Pipe Muffler Size Muffler End Tip Style California Emissions FALSE Product Disclaimer Fitment Note Does NOT fit any 2010 2011 models Fitment Note Does NOT fit YFZ450R or YFZ450X models Fitment Note Fitment Note Fitment Note Larger diameter than stock head pipe