YAMAHA WATER PUMP BODY 68D-G4311-01 PAF4-03000019

Function and technical context

The water pump body is the central structural component of the engine cooling system. It houses the impeller and internal ducts that allow forced circulation of coolant through the engine galleries, maintaining operating temperatures within optimal ranges. This part works under constant pressure and is especially critical in marine engines, where salt or contaminated water accelerates the wear of their internal surfaces. A deteriorated, cracked or body with lime deposits drastically reduces the efficiency of the coolant flow, causing overheating, loss of power and risk of engine seizure.

When to replace this part?

The most obvious symptoms include visible leaks around the mounting flange, progressive overheating of the engine even with the cooling system running, or obstruction of the internal water passages by limescale deposits. Although there is no fixed replacement interval for the pump body, it is recommended to inspect it at each seasonal inspection, especially if you operate in waters with high salinity or sedimentation. Replacing this part preventively when you have detected the first symptoms avoids costly breakdowns and the risk of running out of cooling while sailing.

Compatible Yamaha engines

Equivalent manufacturer part numbers