Membrane Kit 15170-91J00

Function and Technical Context

This membrane kit is part of the fuel supply system in small-displacement outboard motors, acting as a flexible element in the diaphragm fuel pump. The membranes seal and create the working chambers that allow fuel suction and delivery from the tank to the carburetor, ensuring constant flow and leak-free operation. Over time, the rubber or polymeric material of the membranes deteriorates due to continuous contact with gasoline and modern additives such as ethanol, losing elasticity and causing fuel supply failures. Replacing the complete kit guarantees full restoration of pumping function without leaving worn components in the circuit.

When to Replace This Part?

The most common symptoms of a worn fuel pump membrane are difficult or impossible cold starting, engine stalling under load, sudden stops at cruise speed, and irregular operation with power loss. It is recommended to inspect and replace the membranes at each seasonal service or in case of any fuel supply problems, especially if the motor has been in service for more than two seasons or has been stored with fuel in the circuit. Changing this kit preventively is much more economical than suffering a breakdown due to fuel starvation or facing major carburetor repair due to contamination.

Compatible Johnson/Evinrude Engines

Equivalent Manufacturer References