I have a 2012 25 efi Mercury on our pontoon that we occasionally rent to guests at our Inn. 2 weeks ago the fuel pump filled the crank case full of gas so I drained the oil, put new oil and filter in and installed a new fuel pump. Seemed to run fine so this weekend we had some people using it and worked fine on Saturday. On Sunday it was warmer and sunny the went to a quiet spot on the lake and anchored, just sitting in the sun. When they were going to leave the motor wouldn't start. I went to the rescue and tried everything I could do without tools on the lake but it wouldn't fire at all. Towed it back to the dock and left it sit overnight. This morning it started like it normally does and ran fine. Now I am nervous about sending others out with it. Any ideas what would cause this problem?
