The Kawasaki BN125 Eliminator uses 1073 and P21W bulb sizes for both front and rear turn signal applications. A replacement chart covering 2001 to 2009 model years documents the bulb size specifications for this motorcycle.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The two bulb types specified across all model years of the Kawasaki BN125 Eliminator's turn signal positions are the 1073 and the P21W. Both share the BA15s single-contact bayonet base, meaning the physical mounting interface is identical between the two types.
Despite sharing the same BA15s base, the 1073 and P21W are not electrically equivalent. The 1073 operates at 12V and 13W under the ANSI standard used in the United States and Canada, while the P21W operates at 12V and 21W under the ECE standard applied in Europe and other markets. The wattage difference of 8W means the two types draw meaningfully different current loads.
The 1073 is a lower-wattage variant of the more widely known 1156 bulb. Both are single-filament types with the BA15s base, but the 1073 produces less light output and draws less power, which reflects its intended use in signalling applications rather than primary illumination.
The front turn signal position on the BN125 Eliminator used the P21W for model years 2001-2008, with the exception of 2007, which specified the 1073. The 2009 model year also specified the 1073 for the front position.
The rear turn signal position shows a different pattern. The 1073 was specified for the 2001-2002 model years, the P21W was specified for 2003-2008, and the 1073 returned for the 2009 model year.
Because the 1073 and P21W share the BA15s bayonet base, one bulb can be physically inserted into a socket designed for the other. However, substituting a P21W where a 1073 is specified introduces a higher wattage load that the original circuit may not have been designed to handle, and substituting a 1073 where a P21W is specified produces lower light output than the original design intended.
The 2007 front turn signal position is notable in that it specified the 1073 while the rear position for the same year specified the P21W, meaning the front and rear turn signal bulbs for that model year were not interchangeable on a like-for-like basis despite sharing the same base type.
The P21W designation is defined by ECE Regulation No. 37, which governs filament bulbs used in lighting and light-signalling devices for motor vehicles. The "21W" in the designation directly reflects the rated wattage, and the "P" indicates a prefocus base, though in this case the BA15s bayonet form is the relevant mounting standard.