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Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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Can someone tell me if my fuel pump on a '94 mercury marine

Customer Question

Can someone tell me if my fuel pump on a `94 mercury marine 4.3l engine has a check valve located in the pump itself to prevent back flow while it is sitting idle?
Submitted: 11 months ago.
Category: Boat
Expert:  Tan replied 11 months ago.

Hello. My name is Tan.

The fuel pump does not have a check valve. But the boat has a check valve at the fuel tank where the fuel supply line connects. This is called an anti siphon valve.

What seems to be your issue?

Customer: replied 11 months ago.
Fuel all drains back out of the carb. after sitting over night or for a few hours .course then pump don`t run long enough to prim the carb again to start the engine.
Expert:  Tan replied 11 months ago.

Ok remove the fuel supply line at the fuel tank and unscrew the barbed fitting the hose connected to. Look inside the fitting you should see a check ball. The valve should only allow fuel to flow one way.

Customer: replied 11 months ago.
Ty Tan I`m going out now and try that. Crossing my fingers hoping your right. lol
Expert:  Tan replied 11 months ago.

OK. Let me know what you find.

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