I have a 1992 maxum 1800sr mercruiser i/o 3.0L . The day before it ran fine pulled into dock added fuel cause it was t 1/4 tank. Next day I opened boat cover started it up and it idled rough for about 25 minutes then stalled. I tried to restart it wouldnt start. Its cranking but not starting. About a month ago I had to replace fuel pump so I also changed plugs and wires. There is no water seperator or fuel filter anywhere in sight. I looked all the way from carb to fuel tank nothing. I would really apprieciate any suggestions and advice.