I have a 1986 mercury 90 hp two stoke inline 6. Today I warmed the motor up on the driveway with the muffs and it started quickly and idled fine. I went in the water and it was great. I stopped and fished for a while and it started fine. I hit a few big wakes and the engine sounded different and it felt weak. I got near another fishing spot and began to power down and it shut off. I could only start it by having the idle speed lever all the way up. It would not stay running. I had to rev it up and slam it in gear then trottle up to get home. I put it back on the muffs in the driveway and it started right up and idled fine. I did a forum search until my eyes bled. Others had similar problems, but did not post a follow up.