The Yamaha FZ600 headlight assembly uses HS1 bulb size for both high beam and low beam functions. Replacement chart data covers 1986 to 1988 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 HS1 bulb is the sole bulb type specified across all lighting positions for the Yamaha FZ600, covering both high beam and low beam headlight functions for the 1986-1988 model years.
The HS1 is a dual-filament halogen bulb, meaning a single physical unit contains two separate filaments to serve both high and low beam functions within one housing.
The HS1 operates at 12 volts with a 35W/35W output rating, where each wattage figure corresponds to one of the two filaments, both producing equal wattage in this specification.
The HS1 uses a PX43t base, a bayonet-style fitting specific to motorcycle headlight applications, which is not interchangeable with common automotive bulb bases such as H4 despite the H4 also being a dual-filament halogen type.
The HS1 is governed by ECE (Economic Commission for Europe) standards, a regulatory framework recognized across Europe and numerous other markets worldwide, distinguishing it from bulbs designed solely to SAE (North American) standards.
Because both the high beam and low beam positions share the same HS1 specification across all three model years, a single bulb type serves the entire headlight assembly for the 1986-1988 FZ600.