Wossner 8776DB Piston Kit - 2010-2013 Yamaha YZ450F Size B

Wossner 8776DB Premium Forged 4-Stroke Piston Kit - Size B

Maintain the aggressive power of your fuel-injected Yamaha with the Wossner 8776DB Piston Kit. Specifically engineered for the 2010-2013 Yamaha YZ450F, this Size B forged kit is the professional choice for restoring "Factory Quality" compression and reliability in seasoned cylinders. At Moto-House MX, we understand the demands of the YZ450F’s reverse-cylinder engine design, and Wossner’s aerospace-grade components are built to handle the intense heat and RPM of high-level motocross.

Forged from aerospace-grade aluminum alloy, this piston features advanced radial boss machining and enhanced oiling slots for superior wrist pin lubrication—a critical factor for the longevity of high-performance 450cc engines. The permanent skirt coating reduces internal friction and piston rock, resulting in a quieter-running engine and a faster break-in period. This Size B piston (96.97mm) is tailored for 97.01mm bores, providing the precise fitment needed for cylinders that have seen standard operational wear.

Top Features: Wossner 8776DB Piston Kit

• Standard Size B (96.97mm Piston): Precision-engineered for 97.01mm bores to maintain perfect factory-spec clearances in used cylinders.
• Aerospace Forged Alloy: Superior structural integrity and thermal resistance to withstand the mechanical stress of competitive racing.
• Advanced Lubrication Design: Radial boss machining and annular grooves ensure the wrist pin stays lubricated during high-RPM operation.
• Low-Friction Skirt Coating: Permanent coating minimizes mechanical noise and protects cylinder walls from excessive wear.
• Enhanced Ring Seal: Specialized ring land treatment improves oil control and maximizes combustion efficiency.
• Complete Kit: Includes forged piston, high-performance rings, wrist pin, and pin locks.

Expert Pro-Tip: The 2010-2013 YZ450F was the first generation of Yamaha's rearward-slanted engine. Size B is the ideal selection for an engine refresh where the Nikasil cylinder plating is still in good condition but has experienced microscopic wear. When rebuilding your top end, always check your timing chain for stretch and ensure your valve clearances are within spec to complement your new high-compression forged piston.

Fitment List

Year Range	Vehicle Brand	Vehicle Model
2010-2013	Yamaha	YZ450F

Frequently Asked Questions

Q: What is the difference between Size A and Size B?
A: Size B (96.97mm) is 0.01mm larger than Size A. This slight increase allows you to maintain the proper piston-to-wall clearance as the cylinder wall experiences natural wear over time, preventing "piston slap" and maintaining peak compression.

Q: Does this kit include a gasket set?
A: No, the kit includes the piston, rings, wrist pin, and locks. A complete top-end gasket set is required for a professional rebuild and is sold separately.

Q: Is the 12.5:1 compression ratio standard?
A: Yes, this ratio matches the factory specification for the 2010-2013 YZ450F, making it a reliable choice for both track and off-road use without requiring race fuel.

Recommended Pairings

• Complete Top End Gasket Set: Ensure a professional, leak-free seal for your YZ450F rebuild.
• Motorex Cross Power 4T Oil: Protect your new forged piston with high-performance synthetic lubrication.

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.