512M05700 Wiseco Piston Kit .040 for Yamaha YZ125 1984 57.00 mm

Wiseco Piston Kit for Yamaha YZ125

Wiseco .040 oversize piston kit for the 1984 Yamaha YZ125, cross-referenced to 512M05700 and sized at 57.00 mm to restore top-end compression on a worn or freshly bored cylinder.

Overview

This Wiseco .040 piston kit for Yamaha YZ125 gives 1984 owners a proven top-end rebuild option when the cylinder has been bored to the next oversize. The kit is built around the 512M05700 part number and a 57.00 mm bore, matching the .040 step over stock. Riders and shops rebuilding a tired 1984 Yamaha YZ125 will find this piston kit suits refresh work on a machine that needs compression and ring seal back.

Built For Performance

• Forged piston construction for strength under high-rpm two-stroke loads
• .040 oversize sizing matched to a 57.00 mm bore
• Cross-referenced to part number 512M05700 for easy verification
• Ring, pin, and clip hardware included for a complete top-end install
• Designed as a direct-fit replacement for the 1984 Yamaha YZ125

Fits These Machines

• for Yamaha YZ125, 1984

On-The-Job Use

• Top-end rebuilds after a cylinder bore or hone
• Restoring compression on a high-hour 1984 YZ125
• Race-day refresh between motos or events
• Trail and track riding where reliable ring seal matters

Specs At A Glance

Good To Know

Q: Does this kit require boring the cylinder? A: Yes, a .040 oversize piston is intended for a cylinder that has been bored or honed to 57.00 mm to match. Confirm your current bore before ordering.

Q: Is this an original Yamaha part? A: No, this is a Wiseco piston kit made for the Yamaha YZ125 and is not an original equipment Yamaha part. The 512M05700 reference helps confirm fitment.

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