1995 mercury 50elpt4s runs rough

[wheelers4life]

I have a 1995 mercury outboard. It is a Bigfoot model 4 stroke with carburetors. Model is 50elpt4s. I can run it all day long with no problems. The problem I’m haveing is that when I shut it off and fish for a while it starts up but runs real rough at low rpms under like 2k. One I get it above that it runs good at 17mph. But as soon as I come back under 2k it suns rough and sputters sometimes it will stall out and be real hard to start. I need help please I’m at the end of my rope. I only have 4 marine shops around here and it has been to all 4 but no help. They replaced the stator. Timing belt, plugs, fuel tank, lines, filter, priming bulb, fuel pump.

 

[Faztbullet]

You need to test when its broke. Invest in a timing light and when it acts up test all 4 spark leads for spark. Could be a coil dropping out under heat soak.

 

[wheelers4life]

I have fixed the problem. When I changed the plugs I noticed some oil on the plugs. I did some research on products that could clean an outboard. I run accross a product from BG Called EPR. Engine performance restorer. I put it in and ran the boat for about an hour and let it sit over night. When I drained the oil it was totally black. I finished the oil change and have been running my boat ever since with no problems. I checked the plugs this afternoon and they are dry. I think this did the trick very good product.

 

[jimmbo]

Glad to see you found a Snake Oil that worked. It is usually 2 strokes that get Rings that are stuck because of Carbon buildup.