Kawasaki KFX400 Brake Bulb Size

The Kawasaki KFX400 uses a P21/5W bulb size for brake applications. The replacement chart covers 2003 through 2006 production years with corresponding bulb specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	US Type	EU Type	Shop
2003-2006	1157	P21/5W	Check Price

Bulb Specifications

Description	Type	Shop
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W	Check Price
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157	Check Price

Other Locations

Additional Notes

The P21/5W is the brake bulb type used across all listed model years of the Kawasaki KFX400, covering the 2003-2006 range.
The P21/5W is a dual-filament bulb, with one filament rated at 21 watts for the brake or turn signal function and a second filament rated at 5 watts for the running light function.
The bulb operates on a 12-volt electrical system, which is standard for this class of powersport vehicle.
The P21/5W uses a BAY15d bayonet base, a two-pin offset base design that prevents single-filament bulbs from being seated in its place, as the pin positions are staggered rather than aligned.
The P21/5W is an ECE-rated bulb, meaning it conforms to the Economic Commission for Europe lighting standard, which is recognized across European and many worldwide markets.
Because the BAY15d base is offset, it is not interchangeable with the BA15d base, which shares the same bayonet style but uses evenly spaced pins and is found on single-filament bulbs of similar size.