| Forged from high-silicon aluminum alloy for maximum strength and dependability.. Innovative forging design and piston skirt provide maximum horsepower and torque.. Wiseco High-Performance piston kits are priced with piston, rings, pins and circlips (unless noted otherwise).. Oversize pistons require cylinder sleeving.. SPECIFICATIONS. Displacement: 82cc. Bore - Standard: 47.00mm. Bore - Actual: 48.50mm. Bore - Oversize: 1.50mm. Stroke | 45.60mm. ITEM CONTENTS. 1909CD - 48.50 mm Ring Set. CW12 - ROUND WIRE PIN LOCKS 12MM (PAIR). S538 - PistonPin 12mm x 1.535in. NonChromed SW |