The Yamaha RS90 Nytro headlight bulb uses a 9003 size for both high and low beam functions. The replacement chart covers 2006 to 2007 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 an ANSI-standard designation used in the United States and Canada for a dual-filament halogen bulb with a P43t base, rated at 12 volts with a 60-watt high beam filament and a 55-watt low beam filament.
The Yamaha RS90 Nytro uses the 9003 bulb for both the high beam and low beam headlight positions across the 2006-2007 model years.
Because the 9003 carries two filaments within a single housing, one bulb serves both beam functions rather than requiring separate units for each position.
The P43t base is a standardized bayonet-style fitting with a 43mm collar, which determines physical socket compatibility in the headlight assembly.
The 9003 specification is functionally equivalent to the H4 bulb used under international IEC/ECE standards, though the 9003 designation applies specifically to the ANSI classification system.
Substituting an H4-designated bulb for a 9003 in the RS90 Nytro may be possible due to shared base geometry and electrical ratings, but the designations originate from different standards bodies and confirmation of exact fitment is advisable before substitution.