YAMAHA PUMP MEMBRANE 6J8-24471-00

Function and technical context

The pump diaphragm is an essential component of the water cooling system on Yamaha, Mercury and Mariner outboard engines. This piece works inside the fresh water pump, acting as a dynamic sealing element that allows the controlled movement of the coolant through the internal passages of the engine. Its function is critical to maintain the continuous circulation of cooling water: without a membrane in perfect condition, the pump loses pressurization capacity, the cooling flow rate is drastically reduced and the engine runs the risk of severe overheating, especially when sailing at cruising speed or in warm waters.

When to replace this part?

Pump membranes degrade from continuous exposure to salt water, temperature changes, and compression cycles. The most common symptoms are: weak water flow in the discharge pipe, engine overheating even at reduced speed, loss of pressure in the cooling system, or complete absence of water circulation. It is recommended to inspect the membrane every boating season or every 200-300 hours of operation; Replacing it preventively during annual maintenance prevents unexpected water breakdowns and more costly engine repairs resulting from overheating.

Equivalent manufacturer part numbers