Yamaha YZ 250 F (CG 40) [2019-2021] - forged pistons

PROX forged pistons for Yamaha YZ 250 F (CG 40), 2019-2021

The PROX forged piston is intended for the Yamaha YZ 250 F (CG 40) built between 2019 and 2021. Its forged aluminum design combines the specified standard compression with a shape that is tailored to use in the 4T engine.

Function and execution

The piston is made of a specific aluminum alloy. This design reduces friction and supports reliability in engine operation. The execution corresponds to OEM quality. For the combustion chamber side, the piston has a flat crown with a raised top and 4 valve pockets.

Technical data

• Brand: PROX
• Piston Type: Forged
• Material: aluminum
• Piston compression: standard
• Diameter Ø: 76.96 mm
• Letter oversize: B
• Oversize: +0.01
• Stroke: 4T
• Specificity: Flat crown with raised top / 4 valve pockets

Vehicle assignment

The forged piston fits the Yamaha YZ 250 F (CG 40) from the full 2019-2021 model year range. When making your selection, the diameter Ø 76.96 mm, the letter B and the oversize specification +0.01 should be taken into account in particular.