Restore factory-fresh performance and compression to your dirt bike with the ProX 4-Stroke Piston Kit. Precision CNC-machined in Japan using low-expansion, low-friction alloys identical to major OEM engine builders, ProX pistons offer an economical, ultra-reliable replacement for worn stock pistons.
This "A" size piston (96.95mm) is designed specifically for standard-bore plated cylinders to achieve exact factory piston-to-wall clearances.
Complete Kit: Includes piston, premium ring set, wrist pin, and circlips.
OEM Specs & Compression: Maintains the factory 12.5:1 compression ratio for dependable, stock power delivery.
Precision Japanese Engineering: Machined on state-of-the-art CNC equipment for low friction, high durability, and thermal efficiency.
Direct Drop-In Replacement: Fully interchangeable with OEM part numbers without requiring cylinder mods.
Bore Size: 96.95mm (Standard Size "A")
Compression Ratio: 12.5:1
Part Number: 01.2440.A
Yamaha YZ450F (2010 – 2013