Merc won,t start sometimes

[Jim Almquist]

A buddy of mine has a 2005 75 hp merc 4 stroke that will every now and then just won,t start and then it will be fine for a day or 2.Spark appears to be good but I think that it is not getting gas.When it runs it runs and trolls great. Could it be a electronic fuel pump that is just intermitently quiting? We also put some seafoam in the gas to be sure it was not a bad batch of gas and checked the fuel filter and cleaned it out but that was very clean. Any help so we can fish more with out worry cause it is not a good feeling to be on Winni with a motor you just can,t trust.

[Surface Tension]

Jim, is this happening with the engine cold, warm, or both?

[Jim Almquist]

It seems to happen when it is cold or has sat a while but not when he has just lunched and it is the first time starting for the day. The other thing that was a little weird was that on sat.in the afternoon when he first started having problems it would start and smoke or steam would come out when it first started.It is a 4 stroke so that why it did not seem right to blow oil that maybe water in gas might steam.

[Surface Tension]

Have him check the oil level. Between gas and moisture due to lower operating temps getting in the oil the level could be high. See if that clears anything up.

[Jim Almquist]

Thanks Frank I will give him a call and have him check.

[sptitz]

It's my motor. Oil level is right on, and the oil looks fine (no water).

[Surface Tension]

It could be anything, Its going to be a process of elimination. So add as much info and details as possible. For now I'm going on the smoke deal.

White smoke is from water, blue smoke is oil, and black smoke is from a rich gas mixture. From your post you said white smoke. If its coming out the exhaust then you have water in the gas or its coming from a bad gasket. Water in the gas will sit in the lowest point in the tank. Thats till you hit some good waves and then the water gets mixed into the gas. Remove the filter, using the squeeze bulb pump gas into a glass container. Examine for water. It might be cloudy or is might show as swirly. If you let it sit the water will separate and lay on the bottom. Another way to look for water in the tank is to crank the tongue jack all the way up. Let the boat sit for a while so the water/gas can separate. Now get a siphon hose to the lowest portion of the tank and siphon into a glass container. Do that and see what you find out.

[sptitz]

Thanks for getting back to me. It was blue smoke. I thought too that it would be oil. It did that about 4 times after the first time it wouldn't start. The second and third time it wouldn't start,(when it finally did) their was mo smoke at all, it started right up and no smoke at all. Also when it starts it runs fine, no sputtering at all.

The motor has a sediment (sp?) bowl with a float to detect water and I have not seen any water in there but there certainly were enough waves to stir things up! I will check further for water.