ProX Standard Bore "A" Piston Kit (Part # 01.2440.A)

ProX Standard Bore "A" Piston Kit (Part # 01.2440.A)

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 those used by 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.

Key Features:

• 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.

Specifications:

• Bore Size: 96.95mm (Standard Size "A")   

   

• Compression Ratio: 12.5:1   

   

• Part Number: 01.2440.A   

   

Fitment:

• Yamaha YZ450F (2010 – 2013)