Wiseco PK1820 Pro-Lite Top End Piston Kit Bore - 2-Stroke 88.5mm

The Wiseco PK1820 is a complete Pro-Lite 2-stroke top end piston kit featuring an 88.5mm bore (1.5mm oversize) designed for Yamaha YZ490 and WR500 applications. Part of Wiseco's legendary Pro-Lite line, this kit delivers everything needed to properly rebuild or overbore a two-stroke top end in a single purchase.

Kit Contents:

• 1 Wiseco Pro-Lite forged piston (546M series, 88.5mm bore)
• High-performance piston ring set
• Alloy wrist pin
• Wrist pin circlips
• Complete top end gasket set
• Top end bearing (2-stroke application)

Key Features:

• Forged aerospace alloy construction — dedicated forgings provide a superior strength-to-weight ratio compared to cast pistons
• Pro-Lite design — Wiseco's proven 2-stroke forged piston platform, refined through decades of racing development
• 1.5mm oversize (88.5mm) — ideal for cylinder overbore rebuilds restoring performance and sealing
• All-inclusive kit — complete top end gasket set included so no additional components are required
• Race-proven — Wiseco piston designs are trusted by top race teams across Supercross, Motocross, GNCC, and more
• Compatible with multiple cylinder types — installs in cast iron, chrome, nikasil, and boron composite cylinder bores

Wiseco manufactures all pistons using an in-house forging process at their facility in Mentor, Ohio, allowing full control from raw material to finished part. The PK1820 kit provides a straightforward, one-stop solution for a correct top end rebuild on vintage Yamaha two-stroke motocross and enduro machines.