Yamaha Motor Co., Ltd. 2X5-11601-10-00 Piston Ring Kit

The Yamaha 2X5-11601-10-00 piston ring kit is a genuine Yamaha OEM component designed to restore compression in two-stroke motorcycle engines, commonly installed in Yamaha YZ400 models circa 1979 and similar vintage motocross machines needing piston ring replacement. It is a first oversize kit configured for +0.25 mm, intended to seal the combustion chamber and maintain engine compression in a two-stroke gasoline engine. The kit uses hardened steel piston rings and is aimed at engine rebuilds and repairs, designed for specific piston diameters and cylinder bores. As an OEM part, it is often discontinued or limited in availability, with the Yamaha origin confirming its authentic lineage. Common replacements include Yamaha 2X5-11601-00-00, 2X5-11601-20-00, and 2X5-11601-30-00.