Dayco XTX Extreme Torque Drive Belt
1004-9613 (MFG #: XTX5057)
$203.99
Sale price
$203.99
Regular price
$203.99
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Dayco XTX Extreme Torque Drive Belt for Ski-Doo Formula Plus 521 Snowmobile
Dayco XTX Extreme Torque Drive Belt for Ski-Doo Formula Plus 521 Snowmobile
$203.99
Sale price
$203.99
Regular price
$203.99
SKU:1004-9613
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Description
Bred from a rich history of experienced belt builders, the Dayco XTX belt is specifically engineered to maximize the performance of the most extreme, high horsepower snowmobiles. Beating the competition on the race course is just one of many aspects that sets the XTX belt apart from its competition. Specially formulated high temperature Polymer along with the highest level of engineered reinforcement proves to perform better in belt operating temperature and efficiency than leading competitors. Its innovative break-through design of deeper cogs on top and rounded cogs on the bottom yield the advantages of ultimate flexibility and longer belt life while being a better alternative to the original equipment belt.
Key Features
- Faster and more consistent throttle response at high speeds
- Quicker throttle response at mid-speed acceleration
- Greater secondary acceleration at high RPMs
- Greater secondary acceleration as primary acceleration increases
- Reduction in slippage during the highest levels of torque
- Providing more power to track
- Better performance during deceleration (more responsive engine braking)
- Tested and proven reliability at well over 12,000 RPMs
- Cooler-running temperature than the leading competitors
Technical Specifications
- MFG. Part Number XTX5057
Vehicle Information
Ski-Doo Formula Plus 521 Snowmobile (1985-1991)
The Ski-Doo Formula Plus 521, produced from 1985 to 1991, established itself as a pioneering high-performance trail snowmobile. It debuted with an innovative Independent Front Suspension (IFS) and a robust 521cc liquid-cooled Rotax twin engine, consistently delivering powerful performance throughout its production run. This model featured an all-new chassis with an aluminum tunnel and a Progressive Reaction Suspension (PRS) in the rear, setting new standards for its era. While the core 521cc engine remained, the 1985 model year marked a significant platform introduction, featuring a new chassis and the Type 537 Rotax engine with oil injection. In 1991, a notable performance variant, the Formula Plus X, was introduced. This trim included specific engine enhancements like a different pipe, rotary valve, 38mm carburetors, and additional airbox intakes, alongside a chromoly front bulkhead, to further boost horsepower. Other trims like the LT (Long Track), E, XTC, and XTCE SS/SR were also offered in later years, providing options for different rider preferences. Q: How do I ensure this part fits my specific Ski-Doo Formula Plus 521?
A: To guarantee a perfect fit, please use the year and edition selector at the top of this page. This will filter parts specifically compatible with your snowmobile's exact configuration.
Maintenance
| Component | Interval | Details |
| Oil (Injection System) | Before every ride | Check reservoir level. Use only high-quality 2-stroke injection oil, TC-W3 rated or manufacturer-specific. Two-stroke engines with oil injection systems do not have a traditional engine oil filter. |
| Drive Belt | Inspect every 50 hours or if performance feels off. Replace every 2 400 to 4 800 km. | Inspect for signs of separation, edge cord coming out, glazing, or excessive narrowing. Maintain proper tension and height in the secondary clutch. |
| Spark Plugs | Inspect and replace as needed | As part of regular tune-ups or if performance issues arise. |
| Air Filter | Clean or replace as needed | Often seasonally or based on riding conditions, to ensure proper engine breathing. |
| Coolant | Check before every ride. Replace every 2 years. | Check level when the engine is cold. Use manufacturer-specified coolant or a 50/50 premix rated for powersports. |
The intervals provided are based on general practices for 2-stroke snowmobiles of this era. For the most accurate and detailed schedule, always consult the official Ski-Doo owner's manual specific to your model year.