594M05600 Wiseco Std Piston Kit for Yamaha YZ125 1990-1992 56.00 mm

Wiseco Std Piston Kit for Yamaha YZ125

This Wiseco Standard Piston Kit restores top end performance on 1990 to 1992 Yamaha YZ125 machines, using the 56.00 mm bore size that matches the factory standard cylinder, and cross-references OEM part 594M05600.

Overview

This Wiseco Standard Piston Kit is a 56.00 mm forged piston assembly made to replace a worn or damaged top end on the Yamaha YZ125. The kit restores compression and response so the engine pulls cleanly through the rev range, and it is aimed at riders and mechanics rebuilding 1990 to 1992 YZ125 models. The Standard Piston Kit gives a like-for-like size replacement, keeping the stock bore intact.

Built For Performance

• 56.00 mm standard bore size matches the original Yamaha YZ125 cylinder diameter
• Forged piston construction for strength under high rpm loads
• Precision machined skirt and ring grooves for a consistent seal
• Sold as a kit with piston, rings, wrist pin, and clips
• Reference number 594M05600 aids parts identification

Fits These Machines

• for Yamaha YZ125 1990
• for Yamaha YZ125 1991
• for Yamaha YZ125 1992

On-The-Job Use

• Top end rebuilds on 1990 to 1992 YZ125 motocross bikes
• Refreshing a worn piston before a race season
• Restoring compression on a tired engine
• Workshop service and maintenance repairs

Specs At A Glance

Good To Know

Q: Does the kit include rings and pin? A: Yes, the piston kit is supplied complete with rings, wrist pin, and retaining clips. Verify the 56.00 mm size matches your cylinder before fitting.

Q: Can I fit this without boring the cylinder? A: This kit is the standard size, so it suits a cylinder still within factory spec. Measure bore wear first, as an oversized piston is needed once the cylinder is out of tolerance.

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