Motor runs fine for a bit then randomly slows down then stalls

[jackmurr32]

Hello, I am new to boating and have a small boat with a 8hp Mercury motor. The motor will run fine for a few minutes then randomly slow down and will stall if I try to increase the throttle. I was wondering if it might be something to do with the fuel line or the motor itself? Thanks!

 

[Chris1956]

Pump the fuel line primer bulb. if that fixes it, you have a restriction in the fuel or a weak fuel pump. Is the fuel tank vented?

 

[jackmurr32]

Pump the fuel line primer bulb. if that fixes it, you have a restriction in the fuel or a weak fuel pump. Is the fuel tank vented?

Thank your for your reply, The fuel tank is vented and I have the vent open while using the motor. Today I did notice the bulb did become a bit flat, so I pumped it but it didn’t seem to work. When the motor does stall when I restart it it will run fine again for a bit until it happens again. It hasn’t stalled at low speeds only when increased.

 

[Chris1956]

Flat primer bulb indicates a fuel restriction upstream of it. That would be tank vent issue or some other restriction. Some tanks have fuel filters in the pickup tube. Most have fuel screens on the tank pickup. Some fuel tanks have dirt that clogs the fuel screen

Alternatively, Check the fuel filters. If clogged clean or replace them. If that doesn't fix it, rebuild the fuel pump.

 

[jackmurr32]

Flat primer bulb indicates a fuel restriction upstream of it. That would be tank vent issue or some other restriction. Some tanks have fuel filters in the pickup tube. Most have fuel screens on the tank pickup. Some fuel tanks have dirt that clogs the fuel screen

Alternatively, Check the fuel filters. If clogged clean or replace them. If that doesn't fix it, rebuild the fuel pump.

Flat primer bulb indicates a fuel restriction upstream of it. That would be tank vent issue or some other restriction. Some tanks have fuel filters in the pickup tube. Most have fuel screens on the tank pickup. Some fuel tanks have dirt that clogs the fuel screen

Alternatively, Check the fuel filters. If clogged clean or replace them. If that doesn't fix it, rebuild the fuel pump.

Thank you, I was unaware of the fuel filters on the pickup tube. I will definitely take a look at that first thing when I get back out. I appreciate the help