Wossner 8630DA Piston Kit - 2006-2009 Yamaha YZ450F / 2013-2015 Gas Gas EC 450F Size A

Wossner 8630DA Standard Series Forged 4-Stroke Piston Kit - Standard Size A

Refresh your engine’s reliability and power with the Wossner 8630DA Piston Kit. Specifically engineered for the 2006-2009 Yamaha YZ450F and the 2013-2015 Gas Gas EC 450F, this Standard Series forged kit is the professional choice for restoring "Factory Quality" performance. At Moto-House MX, we know these 5-valve and early 4-valve Yamaha-based platforms are legendary for their durability; Wossner’s aerospace-grade forged components provide the precision fitment needed to keep these workhorses charging on the track or trail.

Forged from aerospace-grade aluminum alloy, the 8630DA maintains a reliable 12.3:1 compression ratio, providing smooth, consistent power delivery and excellent heat resistance. Wossner incorporates advanced features like radial boss machining and enhanced oiling slots for superior wrist pin lubrication—a critical upgrade for high-displacement 4-stroke engines operating under heavy loads. The permanent skirt coating minimizes internal friction and piston rock, resulting in a quieter running engine and a more efficient break-in period. This Standard Size A piston (94.96mm) is precision-matched for 95.00mm bores, perfect for a top-end refresh that restores your machine to its original factory tolerances.

Top Features: Wossner 8630DA Piston Kit

• Standard Size A (94.96mm): Precision-engineered for 95.00mm bores to maintain factory-spec clearances and maximum engine life.
• 12.3:1 Compression Ratio: Matches original performance specifications for reliable power and compatibility with premium pump fuel.
• Standard Series Forging: Significantly stronger and more durable than OEM cast pistons, ideal for the high-impact stress of motocross and off-road racing.
• Enhanced Lubrication Design: Radial boss machining and annular grooves ensure the wrist pin stays lubricated during intense, high-RPM operation.
• Low-Friction Skirt Coating: Permanent coating reduces drag and protects your cylinder walls from premature wear.
• Complete Assembly: Kit includes the forged piston, high-performance rings, wrist pin, and pin locks.

Expert Pro-Tip: The 2006-2009 YZ450F is famous for its robust engine, but peak performance requires maintaining tight tolerances. Size A is the ideal choice for a cylinder that is still within factory service limits. When performing a rebuild with the 8630DA, we recommend inspecting your valve train and replacing the cam chain to ensure total engine harmony. Always use a fresh top-end gasket kit and high-quality synthetic oil to provide a professional-grade seal and protect your new forged assembly.

Fitment List

Year Range	Vehicle Brand	Vehicle Model
2006-2009	Yamaha	YZ450F
2013-2015	Gas Gas	EC 450F

Frequently Asked Questions

Q: Is this a Standard Size piston?
A: Yes, this is the 94.96mm piston designed for the standard 95.00mm bore. It is the correct choice for cylinders that are new, freshly replated, or within original factory limits.

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

Q: Why choose Wossner for my Yamaha or Gas Gas?
A: Wossner forged pistons are denser and stronger than stock cast parts. They are specifically designed to handle the thermal and mechanical stresses of high-performance racing more effectively, providing superior durability for your 450.

Recommended Pairings

• Complete Top End Gasket Set: Ensure a professional, leak-free seal and proper engine compression.
• Motorex Cross Power 4T Oil: Premium synthetic lubrication specifically designed for high-performance 4-stroke engines.

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.