FUEL PUMP MEMBRANE 84265M

Function and technical context

The fuel pump membrane is the sealing and pressure element that controls the flow of petrol from the tank to the carburetor or injection system of the marine engine. It works within the fuel supply system, subject to continuous cycles of compression and expansion that generate the necessary pressure to stably supply fuel to the engine. Its condition is critical: a worn or cracked membrane generates internal leaks, pressure drops, difficult starts and loss of power during navigation, compromising both the performance and safety of the boat.

When to replace this part?

Characteristic symptoms include difficulty starting especially when cold, irregular engine operation at low revolutions, loss of power during acceleration and the presence of fuel in the crankcase or oil tank. Fuel pump membranes require annual inspection before each boating season and preventive replacement every two to three years of regular use, or sooner if leaks are detected. Changing the membrane preventively avoids unexpected accidents at sea and costly repairs to injection systems damaged by contaminated fuel.

Mercury/MerCruiser

Equivalent manufacturer part numbers