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

PROX forged pistons for the Yamaha YZ 250 F

The PROX forged piston is designed for the Yamaha YZ 250 F (CG 40), built in 2019. Its forged aluminum construction and OEM-equivalent quality make it a suitable component for upper engine revamping.

Function and execution

The aluminum alloy used is designed to reduce friction and support reliability. The piston has a flat crown with a raised top and 4 valve pockets. This shape is specially tailored to the specified engine version.

Technical data

• Brand: PROX
• Piston Type: Forged
• Material: aluminum
• Piston compression: standard 13.5/1
• Diameter Ø: 76.97 mm
• Letter oversize: C
• Oversize: +0.02
• Rings Quantity: Set
• Stroke: 4T
• Specificity: Flat crown with raised top / 4 valve pockets

Vehicle assignment

The forged piston fits the Yamaha YZ 250 F (CG 40), built in 2019. The assignment refers to this complete vehicle type and year of manufacture.

Selection note

When making the selection, the diameter of 76.97 mm, the oversize letter C and the oversize dimension +0.02 must be taken into account in particular. The default compression specified is 13.5/1.