Honda Motorcycle CBR600F F4 front turn signal bulb uses 1034 size while rear turn signal bulb uses P21W size. Replacement chart covers 1999 to 2000 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 Honda Motorcycle CBR600F F4 uses two distinct bulb standards across its front and rear turn signal positions for the 1999-2000 model years.
The front turn signal on the CBR600F F4 takes a 1034 bulb, which follows the ANSI standard used in the United States and Canada.
The 1034 is a dual-filament bulb operating at 12V with a 21/5W output, mounted on a BAY15d bayonet base.
As a variant of the 1157, the 1034 shares the same general construction but is designated under a separate ANSI part number.
The rear turn signal uses a P21W bulb, which conforms to the ECE standard applied across Europe and much of the world.
The P21W is a single-filament bulb rated at 12V and 21W, seated in a BA15s bayonet base.
The BAY15d base on the 1034 and the BA15s base on the P21W are not interchangeable, as the former has offset pins to prevent incorrect installation while the latter has a single-contact, symmetrical pin arrangement.
The dual-filament nature of the 1034 distinguishes it functionally from the single-filament P21W, meaning the two bulbs serve different circuit configurations despite both being used as turn signals on the same motorcycle.