Big Bore Kit - 80mm - 9.0:1 - XS650 - 1974-1984 - With Top End Gaskets

The ultimate complete bolt-on Big Bore 750cc Cylinder and Piston Kit - specifically made for the Yamaha XS650 - includes all gaskets seals and o-rings needed for a top job. 

This is a modified limited-production European race engine cylinder block with enlarged fins for improved cooling. The new cylinder block has longer fins matching the head fin length. The precision-machined 447-type pistons feature valve pockets that are cut for large valves and an oil channel for enhanced piston pin oiling.

Kit Includes:

• (1) XS Performance Big Bore Race Cylinder Block (with sleeves installed and finished)
• (2) 80mm Forged Big Bore Pistons (9:1 compression)
• (2) 80mm Piston Ring Sets
• (2) Piston Pins and Clips (internally tapered to ends for weight reduction)

Gaskets / Seals / O-Rings: 

• (1) Big Bore Head Gasket
• (1) Big Bore Base Gasket
• (4) Cylinder Head Sealing Washers
• (1) Top-End Engine O-Ring Set
• (4) Tappet Cover O-Rings
• (1) Top End Copper Washer Kit
• (1) Cam Chain Adjuster Nut O-Ring
• (2) Breaker Housing Gaskets
• (2) Camshaft Oil Seals
• (2) Headpipe Exhaust Gaskets
• (2) Copper Drain Plug Gaskets

Fitted with our XS Performance products (see related parts) and a free-flowing exhaust will result in about 65 Rear Wheel Horsepower or more and 50 foot-pounds of torque!