222M04850 .060 Piston Kit for Yamaha GT1 MX80 1973-1982 48.50 mm

Wiseco Piston Kit for Yamaha GT1 & MX80

This Wiseco 222M04850 piston kit, sized at 48.50 mm with a .060 oversize bore, is a forged replacement piston assembly for Yamaha GT1 and MX80 engines and restores compression and cylinder sealing on worn top ends.

Overview

This Wiseco piston kit for Yamaha GT1 and MX80 models, part 222M04850, gives you a forged piston and matching components sized at 48.50 mm for a .060 oversize bore. The piston kit is built for riders and mechanics rebuilding worn or scored top ends on 1973 to 1982 Yamaha GT1 and MX80 machines. Each piston kit is produced to Wiseco 222M series dimensions so it drops into a freshly bored cylinder.

Built For Performance

• Forged aluminum piston construction for strength under combustion heat and load
• 48.50 mm diameter sized for a .060 oversize cylinder bore
• Wiseco 222M04850 part number identifies the exact piston and ring configuration
• Designed for the Yamaha GT1 and MX80 1973 to 1982 engine family
• Kit format includes the piston and matching components for a top-end rebuild
• Oversize bore sizing restores cylinder wall clearance after honing or reboring

Fits These Machines

• for Yamaha GT1
• for Yamaha MX80

On-The-Job Use

• Top-end rebuilds on worn or scored Yamaha GT1 and MX80 cylinders
• Restoring compression after a seize or ring failure
• Oversize rebore service on a cylinder that has already been honed past spec
• Vintage two-stroke engine refresh on 1973 to 1982 Yamaha machines

Specs At A Glance

Good To Know

Q: Do I need to bore my cylinder to use this piston? A: Yes, this piston is sized at 48.50 mm for a .060 oversize bore, so the cylinder must be bored or honed to match that clearance before assembly.

Q: Can I install this myself? A: A top-end rebuild requires precise cylinder measurement, ring gap checking, and correct torque specs, so it is best handled by a machinist or experienced mechanic for the Yamaha GT1 or MX80.

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