My 1985 merc mr 200 (5.0l GM) stalled today. It ran fine at idle and at slow speed. I ran it at about 3200 rpm for a couple minutes and it seemed to sputter a bit. I backed off and it ran rough all the way back to the mooring where it stalled. It started up no problem right after and idled fine. Could it be water in the gas or a fuel pump problem?
