BMW Motorcycle R90 headlight bulbs utilize a 9003 bulb size for both high beam and low beam applications. The replacement chart covers vehicle production spanning 1973 to 1976.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 bulb is the specified size for both the high beam and low beam headlight positions on the BMW Motorcycle R90 across the 1973-1976 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 within one housing.
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 bayonet-style fitting with a 43mm collar, and this base type determines physical socket compatibility in the headlight housing.
The 9003 designation follows the ANSI standard applicable in the United States and Canada, which defines the bulb's electrical and physical characteristics within that regulatory framework.
Because the 9003 serves both beam positions on the BMW Motorcycle R90, the high beam and low beam headlight sockets accept the same bulb type, and substituting a single-filament bulb in either position would not be compatible with the dual-filament socket design.