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Designed and manufactured in Germany by Wössner, this forged piston is aimed at motocross riders seeking an original engine part for reboring. Machined from aluminum, it features a friction-treated skirt and geometry adapted to the stresses of 2-stroke and 4-stroke engines.
The forging process gives the piston a homogeneous structure, suitable for the cyclic loads encountered in motocross. The skirt finish reduces friction against the cylinder, facilitating tuning during reboring and break-in. This replacement part is designed for oversize bores (letter B) and is installed in conjunction with an appropriate cylinder kit.
Compatibility (examples): YAMAHA YZ 426 F (CJ01) 2001-2002, YAMAHA WR 426 F (CJ02) 2002. Always check the bore diameter and engine specifications before installation.