Ski-Doo MX Z 550 X Brake Bulb Size

The Ski-Doo MX Z 550 X brake utilizes 921 and 1157 bulb sizes for the lighting components on the vehicle. Data for the specific bulbs covers the range from 2006 through 2009.

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
2007-2009	921	W16W	Check Price
2006	1157	P21/5W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921	Check Price
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157	Check Price
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W	Check Price

Other Locations

Additional Notes

The Ski-Doo MX Z 550 X uses two distinct brake bulb types across its model years: the 921 for 2007-2009 and the 1157 for 2006.
The 921 is a T15 wedge-base bulb operating at 12V and 16W. Its wedge base means it is held in place by friction rather than a locking mechanism, requiring no rotation during installation or removal.
The 1157 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with a 21W main filament and a 5W secondary filament. The dual-filament design allows it to serve both a brighter active state and a dimmer standby state within a single housing.
Both bulb types conform to ANSI standards recognized in the United States and Canada, placing them within a widely available standardized classification system.
The 921 and 1157 are not interchangeable. Their base types differ physically, with the 921 using a wedge fitting and the 1157 using a bayonet fitting, making cross-year substitution incompatible without a socket adapter.
The wattage difference between the two bulbs is notable. The 1157's 21W primary filament draws more power than the 921's single 16W filament, reflecting the functional difference between a single-filament and a dual-filament design.