Wossner 8303DB Piston Kit - 2018-2021 Sherco 125 SE-R SC Standard Size B

Wossner 8303DB Standard Series Forged 2-Stroke Piston Kit - Standard Size B

Refresh your French-built enduro machine with the precision of the Wossner 8303DB Piston Kit. Specifically designed for the Sherco 125 SE-R and SC models (2018-2021), this "Size B" forged kit is the expert choice for riders performing a mid-season refresh or scheduled top-end maintenance. At Moto-House MX, we understand that high-performance 125cc enduro engines demand perfect tolerances to maintain their torque and over-rev; this +0.01mm Size B kit provides the exact fitment required to compensate for minor cylinder wear and keep your Sherco running at its peak.

Forged from high-performance aerospace aluminum alloy, the 8303DB is engineered to withstand the unique stresses of technical off-road riding and extreme enduro. It features a dual-ring configuration, which offers superior cylinder sealing and enhanced heat transfer from the piston to the cylinder wall—critical for maintaining consistent power during slow-speed, high-load technical climbs. To ensure maximum service life, Wossner applies a permanent molybdenum disulphide skirt coating that reduces friction and prevents piston rock. Precision-machined for 54.01mm bores, this 53.94mm piston kit ensures your Sherco remains as agile and responsive as the day it left the factory.

Top Features: Wossner 8303DB Piston Kit

• Standard Size B (53.94mm): Precision-machined for 54.01mm bores to restore ideal piston-to-wall clearances in cylinders with minor wear.
• Dual Ring Configuration: Provides an exceptional secondary seal and improved cooling efficiency, ensuring a broader and more reliable powerband.
• Aerospace-Grade Forged Alloy: Significantly stronger and more heat-resilient than OEM cast pistons, offering superior structural integrity under extreme racing conditions.
• Low-Friction Skirt Coating: Permanent skirt treatment minimizes internal drag and protects the cylinder walls for a quieter running engine and smoother break-in.
• Optimized Reciprocating Mass: Expertly machined for lightness to ensure the Sherco 125 maintains its quick-revving, agile engine characteristics.
• Complete Assembly: Includes the forged Size B piston, performance rings, wrist pin, and circlips.

Expert Pro-Tip: Sherco 125cc engines are highly tuned for enduro performance. When your cylinder measures slightly beyond the original factory Size A spec, moving to a Wossner Size B (53.94mm) is the standard professional method to restore perfect mechanical tolerances. Always use a precision bore gauge to confirm your cylinder measures 54.01mm before installation. For a professional-grade rebuild, always install with a fresh top-end gasket kit and utilize premium 2-stroke oil to protect your forged assembly during the critical break-in period.

Fitment List

Year Range	Vehicle Brand	Vehicle Model
2018-2021	Sherco	125 SE-R Racing
2019	Sherco	125 SC
2018	Sherco	125 SE-R

Frequently Asked Questions

Q: Why should I choose a Size B piston?
A: Size B (53.94mm) is 0.01mm larger than Size A. It is typically used for your second or third top-end rebuild to account for the microscopic wear that occurs on the cylinder walls, ensuring you maintain the tight seal necessary for maximum horsepower.

Q: Is this kit compatible with both the SE-R and SC models?
A: Yes, this kit is specifically designed to fit the Sherco 125 SE-R and the 125 SC cross-country models within the 2018-2021 range.

Q: Does this forged piston require a different break-in than stock?
A: Forged pistons expand more than cast ones. It is recommended to perform 2-3 full heat cycles (allowing the engine to cool completely between each) before riding at a full race pace to ensure the rings and piston seat properly.

Recommended Pairings

• Complete Top End Gasket Set: Vital for ensuring a leak-free rebuild and maintaining the correct squish gap for peak performance.
• Motul 800 2T Factory Line: High-performance lubricant to ensure your new forged piston stays protected in technical enduro conditions.

Restore your machine’s power and precision today. Buy now at Moto-House MX!

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