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This Wossner forged piston kit is designed for the 1997 Yamaha YZ125 and features a 54.00mm standard bore. Manufactured in Germany, it is built to deliver structural integrity and efficient thermal performance in high-revving two-stroke engines. The elliptical piston design ensures uniform surface contact under heat expansion, preventing localised stress and reducing the risk of piston collapse. The kit is optimised for effective combustion heat transfer to the cylinder wall, supporting engine reliability.
Features
Forged piston construction for high mechanical strength
Elliptical profile ensures consistent expansion and even load distribution
Reduces risk of structural failure under thermal stress
Promotes efficient heat transfer from the combustion chamber
German-engineered for precision and durability
Specifications
Bore Size: 54.00mm (Standard)
Actual Diameter: 53.94mm
Compression Height: 28.00mm
Stroke: 54.50mm
Displacement: 124 cm³
Piston Clearance: 0.06mm
Compression Ratio: 2-stroke (Wossner and OEM)
Cross-Reference OEM Part Numbers
Wossner Piston Kit Part No: 8117DA
Lock: CW15
Pin: WP032
Ring Set: RSB5400
Rod: P2019
OEM Reference: 4XM-11631-30-A0
Cross Reference: 693M05400
Vehicle Fitments
1997 Yamaha YZ125