Slow Running issue

[Lynn Dykgraaf]

I'm new to the forum. Hope you guys can help. My 93 115 hp inline 4 two stroke Merc will quit running after a while of idleing about. If I am quick and pump my fuel line bulb everything is fine for a bit. The carbs run low on fuel again after a bit of idle time. Maybe 3 to 5 minutes worth. I have replaced the fuel line, checked the fuel filter, checked all connections at the tank. Is the peoblem my fuel pump? Has anyone heard of this before?

Thanks in advance for the help.

Lynn Dykgraaf
Blynndykgraaf@aol.com

 

[MercFan]

Re: Slow Running issue

It sounds like your fuel pumps are worn to the point that at low rpm the pumps are unable to get fuel to your carbs.
The rebuild kits are cheap enough to simply take a chance and replace them.

 

[j_martin]

Re: Slow Running issue

It sounds like your fuel pumps are worn to the point that at low rpm the pumps are unable to get fuel to your carbs.
The rebuild kits are cheap enough to simply take a chance and replace them.

Lead pipe cinch fuel pump is the problem.

 

[mercerfisherman]

Re: Slow Running issue

I won't dispute that it may be your fuel pump, however, when you changed your fuel line, did you replace the bulb... or do you know that the bulb is in good working condition? Might want to doublecheck the bulb.

 

[Lynn Dykgraaf]

Re: Slow Running issue

Thanks for the confimation. Fuel pump looks to be the issue. When I changed out the hose I replaced the entire hose including the bulb. The local shop seems to feel that the pump is at issue as well. The only thing that bothers me is that at anything above idle my engine runs perfectly. Still, the pump is cheap to rebuild. The engine is 14 years old with no major issues to date. I guess a new pump is a small price to pay to work out the problem.

Thanks for the thoughts.


Lynn

 

[MercFan]

Re: Slow Running issue

The other thing that could also be responsible for this behavior, especially since you did replace the fuel line, is a small leak at either end of the replaced pipe. If you have a small leake the fuel pumps will draw in air from that leak, since it's easier to air than fuel. Worth a look to double check those clamps.