797M05450 Wiseco Piston Kit .020 for Yamaha YZ125 2002-2004 54.50 mm

Wiseco .020 Piston Kit for Yamaha YZ125

This Wiseco .020 overbore piston kit for Yamaha YZ125 restores top end performance on 2002 to 2004 models, cross referencing 797M05450 and a 54.50mm bore size.

Overview

This piston kit for Yamaha YZ125 gives riders a complete top end solution for 2002 through 2004 models that need a fresh bore and piston. Built to Wiseco spec at .020 over, the 54.50mm kit replaces worn or damaged components and brings compression and power back to spec. It suits riders doing their own top end work and shops rebuilding 125cc two stroke motocross engines.

Built For Performance

• Forged piston construction for strength under high rpm two stroke loads
• .020 overbore sizing at 54.50mm to clean up worn cylinder walls
• Kit includes piston, rings, wrist pin, and circlips for a complete top end refresh
• Cross references 797M05450 for easy parts matching
• Designed for the 2002 to 2004 Yamaha YZ125 engine platform
• Precision machined ring grooves for consistent sealing and compression

Fits These Machines

• for Yamaha YZ125 2002
• for Yamaha YZ125 2003
• for Yamaha YZ125 2004

On-The-Job Use

• Top end rebuilds after a piston seizure or worn rings
• Cylinder reconditioning when a bore job is needed
• Routine race season maintenance on two stroke motocross bikes
• Restoring compression on a high hour trail or track machine

Specs At A Glance

Good To Know

Q: Does this kit require a cylinder bore? A: Yes, a .020 over piston is sized for a cylinder that has been bored and honed to match, so confirm machine work is done before install.

Q: What comes in the kit? A: A Wiseco piston kit of this type typically includes the piston, rings, wrist pin, and circlips needed for a top end rebuild.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.