Wossner 8104DC Piston Kit - 2002-2026 Yamaha YZ85 2-Stroke Size C

Wossner 8104DC Premium Forged 2-Stroke Piston Kit - Size C

Keep your mini-racer at the front of the pack with the Wossner 8104DC Piston Kit. Specifically engineered for 2002-2026 Yamaha YZ85 cylinders that require a Size C fitment, this kit is designed to restore Factory Quality power and high-RPM reliability. At Moto-House MX, we understand that small-bore racing engines demand absolute precision, which is why we provide Wossner’s aerospace-grade forged components to keep your Yamaha 85cc engine performing at its peak.

Forged from premium aluminum alloy, this piston offers superior structural integrity and heat resistance compared to standard cast pistons. The permanent skirt coating is a vital feature, reducing internal friction and piston rock for a quieter engine and improved mechanical longevity. This Size C piston (47.47mm) is designed for cylinders with a 47.52mm bore, providing the precise clearances needed for optimal compression and power delivery in seasoned cylinders.

Top Features: Wossner 8104DC Piston Kit

• Standard Size C (47.47mm): Precision-engineered for 47.52mm bores to maintain perfect tolerances in used cylinders.
• Aerospace Forged Alloy: Maximum durability and thermal stability, built to withstand the high RPMs of competitive motocross.
• Low-Friction Skirt Coating: Permanent coating reduces wear and mechanical noise for a more efficient engine.
• Single-Ring Racing Design: Optimized for reduced drag and maximum high-RPM efficiency in the 85cc class.
• Complete Assembly: Kit includes the forged piston, high-quality ring, wrist pin, and clips.

Expert Pro-Tip: The Yamaha YZ85 is a high-performance machine that rewards proactive maintenance. Size C is the ideal selection for a cylinder that has seen standard use, as it compensates for the natural microscopic wear of the Nikasil plating. To ensure maximum performance, always inspect your power valve assembly and use a new top-end gasket kit for a perfect seal.

Fitment List

Year Range	Vehicle Brand	Vehicle Model & Size
2002-2026	Yamaha	YZ85

Frequently Asked Questions

Q: What is the difference between Size A, B, and C?
A: Size C (47.47mm) is slightly larger than Size A or B. This allows you to maintain the factory-specified piston-to-wall clearance as the cylinder wall experiences natural wear over time, preventing power loss and ensuring long-term reliability.

Q: Does this kit include the wrist pin bearing?
A: No, the kit includes the piston, ring, wrist pin, and clips. We highly recommend purchasing a new small-end bearing separately whenever you perform a top-end refresh on an 85cc racer.

Q: Will this fit my 2026 YZ85?
A: Yes, this piston kit is fully compatible with the 2002 through 2026 model year Yamaha YZ85 series.

Recommended Pairings

• Top End Gasket Kit: Essential for a professional, leak-free engine rebuild.
• Motorex Cross Power 2T Oil: The ultimate synthetic lubrication choice for high-performance Yamaha 2-strokes.

Restore your Yamaha’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.