The Yamaha XSR900 front turn signal bulb measures P21/5W or 7443 in size, while the rear turn signal bulb measures P21W or 7440 in size. The replacement chart covers 2016 through 2021 model 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.
The 7443 bulb is the most frequently specified front turn signal type across the Yamaha XSR900 range, appearing in the 2016-2020 model years. It follows the ANSI standard used in the US and Canada, operates at 12V, and carries a dual-filament T20 wedge configuration rated at 21W and 5W.
The 7440 bulb holds the same prevalence at the rear, serving as the rear turn signal across the 2016-2020 model years. It is also an ANSI-standard T20 wedge type operating at 12V, but with a single filament rated at 21W only.
The 2021 Yamaha XSR900 front turn signal shifts to the P21/5W bulb, an ECE-standard type used in Europe and worldwide markets. It is a dual-filament bulb rated at 12V, 21W/5W, and uses a BAY15d bayonet base rather than a wedge fitting.
The 2021 rear turn signal uses the P21W, an ECE-standard single-filament bulb with a BA15s bayonet base, rated at 12V and 21W. This differs from the wedge-style 7440 used in prior model years.
The front turn signal bulbs across all listed years are dual-filament types, whether the ANSI 7443 or the ECE P21/5W, both sharing a 21W/5W rating despite differing base designs.
The rear turn signal bulbs across all listed years are single-filament types. The 7440 and P21W share a 12V, 21W rating, but the 7440 uses a wedge base while the P21W uses a BA15s bayonet base, making them physically non-interchangeable.
The base type difference between the 2021 P21/5W (BAY15d bayonet) and the 2016-2020 7443 (T20 wedge) means these front turn signal bulbs are not interchangeable, despite sharing the same wattage ratings.
The BAY15d base of the P21/5W features offset pins that prevent incorrect single-filament bulb installation, a design characteristic relevant to fitment accuracy in the 2021 front turn signal housing.
The ECE bulb designations used in the 2021 model follow international regulations common in European-market motorcycles, while the ANSI designations of the 2016-2020 models reflect North American standardization practices.
Although the 7440 and 7443 share the T20 wedge form factor, the 7443 is dual-filament and the 7440 is single-filament. Substituting one for the other in any listed XSR900 application would result in a wiring or function mismatch.