What is the function of the primer bulb on an outboard motor?

If you’ve ever owned or operated an outboard motor, you may have noticed a small, bulb-shaped device somewhere near the fuel line. This is the primer bulb, and it serves a crucial function in the operation of your motor.

The primary purpose of the primer bulb is to draw fuel from the gas tank and deliver it to the motor’s carburetor. When you squeeze the bulb, a vacuum is created that sucks fuel from the tank and into the fuel line. The bulb also acts as a check valve, preventing any fuel from flowing back into the tank once it has already been drawn into the line. This makes it easier to start the motor and ensures a consistent fuel supply while it’s in use.

Another important function of the primer bulb is to remove any air bubbles that may have formed in the fuel line. These bubbles can disrupt the flow of fuel, leading to sputtering and stalling of the motor. By squeezing the bulb until it’s full and firm, you’re able to purge any air from the line and ensure a steady flow of fuel.

It’s important to note that the primer bulb should be used before every start-up of the motor. This ensures that the carburetor has an adequate supply of fuel and helps prevent damage to the motor. If the bulb feels hard to the touch or doesn’t fill up with fuel, there may be a blockage in the fuel line or a problem with the bulb itself.

The primer bulb plays an important role in the proper function of an outboard motor. Its ability to draw fuel from the tank and remove air bubbles from the line ensures a consistent fuel supply and prevents stalling or damage to the motor. Make sure to use it every time you start up your motor to keep it running smoothly and safely on the water.

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