25 hp mariner hard start

[Fordsnfishin]

Hello yall. Okay what I have is a old 25 horse mariner. It's a 28e # 664 271316.

My problem is the motor seems to be stalling out on me. Most of the time it will start right up and run for several seconds but that wants to die. Than it is very hard to get started back up.

But on other occasions, it will start right up and work perfect, idle great and run great. ..

What could be my issue? Been quite a inconvenience, and hate my boat being unreliable.

Boat has a brand new gas tank, new fuel line, and fresh fuel mixed 50 to 1.

I am cracking the fuel screw when running and priming fuel to motor before I try and start.

Thanks, Zachary

 

[Texasmark]

I am cracking the fuel screw when running and priming fuel to motor before I try and start.

Thanks, Zachary

What does that mean? Are you talking about opening the vent on the fuel tank? What's the history of the engine? Done any carb repair lately? Do a lot of trolling? Engine have a lot of hours on it? Live in a cold climate? Ever try anything like Sea Foam in the fuel to clean out carbon in the combustion chambers and varnish in the fuel system? Checked your fuel pump parts lately for proper operation? Does the fuel primer bulb get good and firm before you attempt to start?

 

[Fordsnfishin]

Yes, I meant opening the vent to the gas tank. History wise, I've owned the boat for 7 years now. It's what I believe to be a 1979 mariner 25hp, been a great motor. This is the first year I've had trouble. It's normally used to make 5 to 10 minute trips at a time, not a whole lot of idle time.

Sea foam is a good thought, I will put some in the fuel to see if that helps.

As far as fuel system goes I'm not sure what else to check.

I played around with it tonight. I primed the bulb and noticed fuel coming out of the fuel line plug where it is connected to the motor. So I replaced that tonight and appears to be getting a better seal as fuel won't come out anymore. So maybe to much air was getting sucked in?

I'm taking it out tomorrow fishing, I'll see if that was the source.

Any other suggestions are appreciated.

 

[Texasmark]

So maybe to much air was getting sucked in?

I'm taking it out tomorrow fishing, I'll see if that was the source.

Any other suggestions are appreciated.

You well may have found your smoking gun. If fuel comes out, your fuel pump can suck air in and cause fuel starvation problems.