The Yamaha WR426F uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers 2001 to 2002 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 is the sole bulb type listed across all headlight positions for the Yamaha WR426F, covering both the 2001-2002 model years.
The 9003 is a dual-filament halogen bulb, meaning a single bulb unit contains two separate filaments to serve both high and low beam functions from one housing.
Because the 9003 handles both beam functions within one bulb, the high beam and low beam headlight positions on the WR426F share an identical part number rather than requiring separate bulb types.
The 9003 operates on a 12-volt electrical system and carries a wattage rating of 60W on the high beam filament and 55W on the low beam filament.
The 9003 uses a P43t base, which is a standardized bayonet-style mount with a 43mm collar, governing physical fitment into the headlight socket.
The 9003 is defined under the ANSI standard and is the designation used in the United States and Canada, making it a region-specific classification for what is otherwise an internationally recognized bulb format.
The 9003 and H4 bulb types share the same electrical ratings and P43t base, and are widely regarded as interchangeable in many fitment contexts, though the 9003 designation reflects the North American ANSI classification while H4 reflects the ECE standard used elsewhere.