790M08150 .020 Piston 81.50mm for Yamaha Wave Runner III GP 700 1994-1997

.020 Piston for Yamaha Wave Runner III GP 700

This Wiseco .020 overbore piston, referenced as 790M08150, brings a 81.50mm bore to the Yamaha Wave Runner III GP 700 700cc two-stroke engine and helps restore compression on a worn top end.

Overview

This .020 piston for Yamaha Wave Runner III GP 700 watercraft is a top-end rebuild component sized at 81.50mm to clean up a lightly worn cylinder. It restores piston-to-wall clearance and compression for the 700cc engine. It suits riders and shops rebuilding a Wave Runner III GP 700 that needs a mild overbore.

Built For Performance

• 81.50mm bore size matches a .020 overbore finished cylinder
• Wiseco forged piston construction for strength under two-stroke heat and load
• Single piston format for replacing one damaged or worn piston
• Oversize sizing restores compression lost to cylinder wear
• Suited to the 700cc two-stroke powerplant in the Wave Runner III GP

Fits These Machines

• for Yamaha Wave Runner III GP 700 1994
• for Yamaha Wave Runner III GP 700 1995
• for Yamaha Wave Runner III GP 700 1996
• for Yamaha Wave Runner III GP 700 1997

On-The-Job Use

• Top-end rebuild after a seizure or lean condition
• Cylinder rebore and hone service work
• Freshwater and saltwater personal watercraft use
• Seasonal maintenance on a high-hour 700cc engine
• Recreational riding and race prep builds

Specs At A Glance

Good To Know

Q: Does this piston fit a standard bore cylinder? A: No, this is a .020 oversize piston meant for a cylinder bored and honed to 81.50mm, so the cylinder must be machined to match before installation.

Q: Do I need to check clearance before fitting it? A: Yes, always measure piston-to-wall clearance against the piston manufacturer's spec and verify jetting after 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.