Wossner 8923DB Piston Kit - KTM Husqvarna Gas Gas 250 SX-F FC250 MC 250F Size B

Wossner 8923DB Premium Series Forged 4-Stroke Piston Kit - Standard Size B

Push your 250cc engine to its absolute limit with the Wossner 8923DB Piston Kit. Precision-engineered for the modern KTM, Husqvarna, and Gas Gas 250 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 high-revving 4-strokes demand perfection; Wossner’s Premium Series forging provides a high-strength, lightweight solution that sustains a massive 14.4:1 compression ratio, ensuring your bike delivers elite-level power and aggressive throttle response.

The 8923DB is a masterclass in small-bore performance, featuring a double-bridged forging design that provides incredible structural integrity for engines that spend their life at the rev limiter. To ensure your engine survives the heat of professional-level racing, 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 78.01mm bores, this 77.97mm Size B kit restores your engine to the tight mechanical tolerances needed for championship-winning horsepower.

Top Features: Wossner 8923DB Piston Kit

• Standard Size B (77.97mm): Specifically designed for 78.01mm bores to compensate for minor cylinder wear and restore factory-correct clearances.
• Ultra-High 14.4:1 Compression: Engineered to maximize combustion efficiency and torque across the entire RPM range.
• Premium 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: Small-bore 250cc race engines are high-tolerance machines. If you are performing a top-end refresh on a cylinder that has logged significant track time, the Size B (77.97mm) is the expert way to account for microscopic cylinder wear while maintaining the tight piston-to-wall clearance required for peak performance. Always use a precision bore gauge to confirm your cylinder measures 78.01mm 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
2016-2022	KTM	250 SX-F / Troy Lee Designs
2016-2022	KTM	250 XC-F
2016-2022	Husqvarna	FC250
2021-2023	Gas Gas	MC 250F
2021-2023	Gas Gas	EX 250F

Frequently Asked Questions

Q: Why should I choose Size B instead of Size A?
A: Size B (77.97mm) 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: What fuel is recommended for 14.4:1 compression?
A: With a very high 14.4:1 ratio, it is highly recommended to use high-quality 93 octane pump gas at a minimum, though many racers prefer a race fuel blend to ensure consistent performance and prevent detonation.

Q: Is the wrist pin included?
A: Yes, this complete Wossner kit includes the forged piston, high-performance rings, the wrist pin, and the circlips.

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.