727M04100 Wiseco .040 Piston Kit for Yamaha YSR50 1987-1992 41.00 mm

Piston Kit for Yamaha YSR50

This Wiseco .040 oversize piston kit for Yamaha YSR50 delivers a 41.00 mm bore replacement piston with rings, wrist pin, and clips, and corresponds to Wiseco part number 727M04100.

Overview

The Wiseco .040 piston kit for Yamaha YSR50 is a replacement piston assembly for riders rebuilding a worn or scored top end. This piston kit for Yamaha YSR50 restores compression and smooth running to 1987 through 1992 YSR50 models. It suits home mechanics and small-bore restorers who want a dependable oversize piston kit.

Built For Performance

• Forged construction for strength under high-rpm small-bore running
• 41.00 mm oversize bore size, .040 inch over standard
• Kit includes piston, rings, wrist pin, and circlips
• Wiseco reference 727M04100 for easy cross-checking
• Designed for the Yamaha YSR50 two-stroke single

Fits These Machines

• for Yamaha YSR50 1987
• for Yamaha YSR50 1988
• for Yamaha YSR50 1989
• for Yamaha YSR50 1990
• for Yamaha YSR50 1991
• for Yamaha YSR50 1992

On-The-Job Use

• Top-end rebuilds after a seize or low compression
• Bore-and-hone jobs that require an oversize piston
• Track and pit bike engines needing a fresh piston
• Restoration of older YSR50 motors

Specs At A Glance

Good To Know

Q: Does this kit come with rings and pin? A: Yes, a Wiseco piston kit of this type normally includes the piston, rings, wrist pin, and circlips. Q: Will I need to bore the cylinder? A: Since it is a .040 oversize piston, the cylinder must be bored and honed to match the 41.00 mm size.

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