Yamaha WR450F Headlight Bulb Size

The Yamaha WR450F uses an HS1 and 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 2003 to 2021 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.

High Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2012-2021	HS1	HS1	Check Price
2003-2006	9003	H4	Check Price

Low Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2012-2021	HS1	HS1	Check Price
2003-2006	9003	H4	Check Price

Bulb Specifications

Description	Type	Shop
ECE standard (Europe & worldwide). Dual-filament halogen motorcycle bulb with PX43t base. 12V, 35W/35W.	HS1	Check Price
ANSI standard (US & Canada). Dual-filament halogen bulb with P43t base. 12V, 60W/55W.	9003	Check Price

Other Locations

Additional Notes

The Yamaha WR450F uses two distinct bulb types across its model years: the HS1 for 2012-2021 and the 9003 for 2003-2006.
Both the HS1 and 9003 are dual-filament halogen bulbs, meaning a single bulb serves both the high beam and low beam functions, which is reflected in the specifications showing identical bulb sizes across both sub-parts for every listed year.
The HS1 operates at 12V with a 35W/35W output, where both filaments share equal wattage across high and low beam functions.
The 9003 operates at 12V with a 60W/55W output, assigning higher wattage to the high beam filament and lower wattage to the low beam filament.
The HS1 follows the ECE standard, which is the regulatory framework used in Europe and internationally, while the 9003 follows the ANSI standard, which applies to the United States and Canada.
Although both bulbs share a visually similar P43t-style base, the HS1 uses a PX43t base and the 9003 uses a P43t base. These two base types are not interchangeable, and substituting one for the other is not supported by the specifications.
The lower wattage of the HS1 (35W/35W) compared to the 9003 (60W/55W) reflects a design consideration common in motorcycle applications, where electrical systems typically operate under tighter power constraints than those found in four-wheeled vehicles.