Wossner 8873DB Piston Kit - KTM Husqvarna Gas Gas 450 SX-F FC450 MC 450F Size B

Wossner 8873DB Pro Series Forged 4-Stroke Piston Kit - Standard Size B

Maintain the elite performance of your 450cc powerhouse with the Wossner 8873DB Piston Kit. Precision-engineered for the modern KTM, Husqvarna, and Gas Gas 450 range, this Standard Size B forged kit is the professional choice for riders performing a top-end refresh on cylinders with moderate hours. At Moto-House MX, we know these machines are the pinnacle of motocross engineering; Wossner’s Pro Series forging provides a high-strength, lightweight solution that sustains a potent 13.6:1 compression ratio, ensuring your bike keeps its aggressive power delivery and lightning-fast throttle response.

The 8873DB is a masterclass in 4-stroke durability, featuring a double-bridged forging design that provides incredible structural integrity for high-RPM racing. To ensure your engine survives the heat of a long moto, Wossner has integrated enhanced piston pin oiling slots and radial boss machining for superior wrist pin lubrication. The piston skirt is treated with a permanent molybdenum disulphide coating to reduce friction and improve break-in performance. Precision-machined for 95.01mm bores, this 94.96mm Size B kit restores your engine to the tight mechanical tolerances needed for maximum horsepower.

Top Features: Wossner 8873DB Piston Kit

• Standard Size B (94.96mm): Specifically designed for 95.01mm bores to compensate for minor cylinder wear and restore factory-correct clearances.
• 13.6:1 Compression Ratio: High-compression design optimized for race-ready performance across the powerband.
• Pro Series Forging: Advanced double-bridged design offers superior strength and heat resistance compared to standard cast alternatives.
• Enhanced Lubrication System: Features specialized oiling slots and annular grooves to ensure consistent wrist pin lubrication under extreme thermal loads.
• Low-Friction Skirt Coating: Permanent skirt treatment reduces internal drag, protects the cylinder wall, and ensures a smoother break-in.
• Complete Kit: Includes the high-performance forged Size B piston, rings, wrist pin, and pin locks.

Expert Pro-Tip: The KTM/Husky/Gas Gas 450cc engine is a high-tolerance racing machine. If you are performing a top-end refresh on a cylinder that has logged significant track time, the Size B (94.96mm) is the expert way to account for microscopic cylinder wear while maintaining a tight piston-to-wall clearance. Always use a precision bore gauge to confirm your cylinder measures 95.01mm before installation. For a professional-grade rebuild, always install with a fresh top-end gasket kit and utilize premium synthetic oil to protect your forged assembly.

Fitment List

Year Range	Vehicle Brand	Vehicle Model
2013-2022	KTM	450 SX-F / Factory Edition
2014-2022	KTM	450 XC-F
2013-2014	KTM	450 SMR
2014-2022	Husqvarna	FC450 / Rockstar Edition
2017-2022	Husqvarna	FX450
2017-2021	Husqvarna	FS450
2021-2023	Gas Gas	MC 450F / Troy Lee Designs
2021-2023	Gas Gas	EX 450F

Frequently Asked Questions

Q: Why should I choose Size B instead of Size A?
A: Size B (94.96mm) is 0.01mm larger than Size A. It is the standard professional choice for an engine that has several hours of use to maintain the tight piston-to-wall clearance necessary for peak horsepower and to prevent piston slap.

Q: Does this piston fit the Rockstar and Troy Lee Designs editions?
A: Yes, this kit is fully compatible with the Husqvarna Rockstar Edition, KTM Factory Edition, and Gas Gas Troy Lee Designs models within the listed year ranges.

Q: What fuel is recommended for 13.6:1 compression?
A: For a 13.6:1 ratio, it is highly recommended to use 91-93 octane pump gas or a race fuel blend to prevent detonation and ensure consistent engine performance.

Recommended Pairings

• Complete Top End Gasket Set: Essential for ensuring a leak-free rebuild and maintaining the correct squish height.
• Premium 4-Stroke Synthetic Oil: Keep your new forged piston and valvetrain protected under high-heat racing conditions.

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.