Yamaha 5X4-12436-00-00 Drive Gear Assembly for Water Pump Drive System

The Yamaha 5X4-12436-00-00 Drive Gear is a precision-machined gear that transfers rotational motion from the crankshaft to the water pump in Yamaha engine cooling systems. Designed for Yamaha YZ125 and similar two-stroke motorcycles, it ensures synchronized operation between the crankshaft and water pump for proper coolant circulation. Made from hardened steel or alloy with an approximate 20-tooth configuration, this gear mounts inside the engine and interfaces with the crankshaft-driven gear train as a genuine Yamaha replacement component. Common replacements include Yamaha 4L0-12436-00-00, 383-12436-00, and 329-13178-00.