546M08700 Wiseco Std Piston Kit for Yamaha YZ490 1984-1990 87.00 mm

Wiseco Std Piston Kit for Yamaha YZ490

This Wiseco Std piston kit for Yamaha YZ490 maintains the factory 87.00 mm bore size and carries OEM cross-reference 546M08700 for standard-bore top end service.

Overview

This Wiseco Std piston kit for Yamaha YZ490 restores stock bore dimensions with an 87.00 mm piston. It is intended for 1984-1990 YZ490 engines that have not been overbored. Riders replacing a worn piston while keeping the original cylinder size will find this kit a straightforward fit.

Built For Performance

• 87.00 mm standard bore size
• Forged aluminum construction for durability under heat
• Precision-machined ring grooves and skirt
• OEM cross-reference 546M08700 for fitment matching
• Complete kit with piston, rings, pin, and clips

Fits These Machines

• for Yamaha YZ490 1984
• for Yamaha YZ490 1985
• for Yamaha YZ490 1986
• for Yamaha YZ490 1987
• for Yamaha YZ490 1988
• for Yamaha YZ490 1989
• for Yamaha YZ490 1990

On-The-Job Use

• Standard-bore top end rebuilds on YZ490 engines
• Refreshing compression without boring the cylinder
• Motocross and off-road riding on high-hour machines
• Routine piston replacement during engine service

Specs At A Glance

Good To Know

Q: Can I use this piston without boring my cylinder? A: Yes, this Std piston matches the original 87.00 mm bore, so no overbore is needed if the cylinder is within spec.

Q: What is included in this piston kit? A: The kit 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.