Yamaha - Gear, driven - 6H4-11537-01-00Yamaha Driven Gear Engine Power Transfer Component 6H4 11537 01 00 Overview When internal gears start wearing out, youll usually hear it before anything elsewhining, grinding, or just not running as smooth. Ive opened up motors where a worn driven gear was the root of the problem, especially on engines that have seen a lot of hours. Its a critical part that keeps everything turning in sync under load. Once its replaced and set up right, the engine