Wossner 8216DC Piston Kit - 1999-2026 Yamaha YZ250 / YZ250X Size C

Wossner 8216DC Premium Forged 2-Stroke Piston Kit - Size C

Maintain the peak performance of your Yamaha 2-stroke with the Wossner 8216DC Piston Kit. Specifically engineered for the Yamaha YZ250 and the cross-country YZ250X, this Size C forged kit is the professional choice for restoring Factory Quality power in cylinders that have seen significant service. At Moto-House MX, we know that the YZ250 is a legend of reliability; Wossner’s aerospace-grade forged components provide the precision fitment needed to keep these iconic machines running strong.

Forged from aerospace-grade aluminum alloy, this piston offers superior structural integrity and heat resistance compared to standard cast alternatives. The 8216DC features a permanent skirt coating to minimize friction and piston rock, ensuring a quieter engine and smoother throttle response. This Size C piston (66.37mm) is precision-matched for cylinders with a 66.42mm bore, providing the exact clearances required for optimal compression and power delivery in older or higher-hour cylinders.

Top Features: Wossner 8216DC Piston Kit

• Standard Size C (66.37mm): Precision-engineered for 66.42mm bores to maintain perfect factory-spec tolerances in cylinders with moderate wear.
• Aerospace Forged Alloy: High-strength aluminum construction built to withstand the mechanical stress of high-RPM 2-stroke racing.
• Low-Friction Skirt Coating: Permanent coating reduces wear on the cylinder walls and provides a quieter engine operation.
• Dual-Ring Design: Optimized for a consistent combustion seal and improved heat transfer for sustained power throughout your ride.
• Complete Assembly: Kit includes the forged piston, high-quality rings, wrist pin, and clips.

Expert Pro-Tip: The Yamaha YZ250 engine is incredibly durable, but Nikasil cylinder plating does experience gradual wear over hundreds of hours of use. Size C is the ideal choice for an engine refresh where the cylinder is still within service limits but has worn beyond the ideal clearance for Size A or B pistons. When rebuilding, always inspect your power valve assembly for carbon buildup and replace your small-end bearing to ensure a professional-grade top-end service.

Fitment List

Year Range	Vehicle Brand	Vehicle Model
1999-2026	Yamaha	YZ250
2016-2026	Yamaha	YZ250X

Frequently Asked Questions

Q: When should I choose Size C?
A: Size C (66.37mm) is 0.02mm larger than Size A. It is used to compensate for natural cylinder wear on high-hour engines. Using a Size C piston restores the proper piston-to-wall clearance, preventing "piston slap" and extending the life of your cylinder.

Q: Does this fit the YZ250X woods model?
A: Yes, the YZ250X uses the same bore and piston configuration as the YZ250 motocross model, making this kit a perfect fit for both machines.

Q: Does this kit include the wrist pin bearing?
A: No, the kit includes the piston, rings, pin, and clips. We highly recommend purchasing a new small-end bearing separately for every top-end rebuild to prevent premature failure.

Recommended Pairings

• Top End Gasket Kit: Essential for a professional, leak-free engine rebuild with a fresh set of gaskets.
• Motorex Cross Power 2T Oil: Premium synthetic protection specifically formulated for high-performance 250cc 2-strokes.

Restore your machine’s power and precision today. Buy now at Moto-House MX!

Moto-House MX – Choice of Champions – is located in Clermont/Montverde, FL. The Best Motocross/UTV & ATV Shop in Central Florida. Stop by our local store in Montverde, FL or enjoy lightning-fast shipping across the USA.