Prox Piston Kit Xl/xr500 `79-82 8.6:1 (90.50mm)

ProX pistons are precision machined on the latest, state of the art CNC equipment. The same low-expansion, low-friction piston alloy is used as is used for all major Japanese engine manufacturers. ProX Piston Kits are a first class solution to replace the original piston in your Motorcycle, Scooter, Moped, ATV, Personal Watercraft, etc. Coated for ultimate performance Most of the ProX pistons come with a coating. Our OEM style Tin coated pistons assist the wear in process when you just started the bike. We have developed a new skirt coating that not only assists the wear in process, but also helps reducing friction after the wear in. The black coating is made from a delicate mix of materials and will increase performance.   Product specifications Attribute Value Additional Info Forged Piston Bore - Actual 90.50 mm Bore - Oversize 1.50 mm Bore - Standard 89.00 mm Boss Space In 27.30 mm Compression Height 18.50 mm Compression Ratio - Actual 8.6:1 Country of Origin USA Cylinders 1 Displacement 498 cc OEM Reference No 13101-429-003 Piston Head Type Flat Piston Pin Hole Diameter 21.00 mm Skirt Coating - Stroke 80.00 mm Total Height 58.50 mm