Description
Yamaha YZ250 YZ250X WR250 Phathead cylinder head kit 1999 2026 CR85 big bore kit 8cc (110+ octane) CR125R9299 Yamaha Chamber Selection:S03 5.9cc (100+ octane) KX112 2014 8cc (110+ octane) Remove the original guts from the stock plastic cap and install into the new billet shell