Mercury Force 40hp sputtering out multiple times

appelt15

Recruit
Joined
Oct 3, 2018
Messages
5
I bought a new-used jon boat the other week with a 1995 mercury force 40hp outboard. Right when i got the boat all i did was clean out the gas tank and put new mix into it. Then the first time i took it out and up river it ran great for about 20-30 minutes with no issues till it all of a sudden just sputtered out and stalled. After that it would start up but almost immediately sputter out. So I let it sit for about 5 minutes and I got it to run for about 3 minutes till it did the same thing and so on and so on till i finally got it back to dock.

This is my first boat so I imagine im wrong but could this be just a dirty fuel filter or maybe the carb is gummed up from sitting. I figure maybe it's just sucking something up that chokes the fuel out and then after sitting for a couple of minutes it pushed it out. I was going to try a new fuel filter and blow out the fuel lines. Also thought I might should check if the fuel pump is operating correctly.

Any feedback would be greatly appreciated
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Primer bulb go flat when this happens? Vent on fuel tank open? Running hot? Until you actually do some checking we can only guess. Plugs -- compression check -- water pump working?
 

appelt15

Recruit
Joined
Oct 3, 2018
Messages
5
The primer bulb never went flat and the vent was open. And it was running regular temp so I don't believe it was an over heating issue. Water pump was also working at the time. I ordered a new carb to see if that will make a difference. Besides that I'm going to replace the old fuel lines and fuel filter and plugs just to be safe. Then I will check back. Thanks
 

appelt15

Recruit
Joined
Oct 3, 2018
Messages
5
I replaced the carb completely, all new fuel lines, new spark plugs, new fuel filter, ran some seafoam thru it and im still having the same problem it just took a slight bit longer for it to present itself this time. Im lost on what to do next.
 

appelt15

Recruit
Joined
Oct 3, 2018
Messages
5
Fuel pump seams to work fine. I put a clear tube on after the pump so I could check it when running it in the yard. I ran it for about 20 min idling in the yard and it worked great. However, I haven't taken it out onto the water and ran it with the cowl off to check.
 
Top