43 V6 Fuel Pump Vent Line

"Hey Guys,
Have a question. I

"Hey Guys,
Have a question. I have noticed that the vent line from my fuel pump to the top plate on carb has fuel in it and is pumping a small amount of fuel into the top of the carb. This is causing rough idle, bogging, and the motor is loading up when shut off.

From my experience the vent tube should not contain any fuel. Correct me if I am wrong here. I plugged the line and motor runs as expected.

Possible diaphram in pump bad ??? Is there a fix or pump replacement needed?

Specs: 1990 4.3L v6 2bl MercCarb

Thanks."

Replace the pump; diaphram is

Replace the pump; diaphram is torn.

"Guy,

Thanks for the respon

"Guy,

Thanks for the responce. Is this a common occurance out of these pumps after such a time period. It is the original pump."

What is the intended purpose o

What is the intended purpose of the vent tube?

Is there any harm in running the line plugged ?

The pump can last 20+ year

The pump can last 20+ years or less. The "vent tube" is there to keep fuel from leaking into the bilge when the diaphragm splits and to tell you the pump is bad.

Running the boat w/the line plugged is a bomb waiting to go off when the fuel starts leaking into the bilge. DON'T DO IT!

Not to mention the diaphram wo

Not to mention the diaphram wont work properly.