I own a 2000 Mercury 965cc outboard motor. The motor started life as a 40hp, but I had a qulaified mechanic upgrade it to a 60 hp, changing the carbs, reeds, etc... I have had absolutely no problems with this motor. My boat has been sitting up for a few months and I wanted to go fishing, so I did some general maintenance on it, ie: changed the lower unit oil, changed the spark plugs, new fresh gasoline, etc. I then started the motor and got it running well. I took the boat out and saw that the cooling system was working as it usually does, so I allowed it to warm up and began to run the boat at about 3/4 throttle. It wasn't just a few seconds of running when the alarm began going off, so I slowed to idle and the alarm stopped. I looked again and saw that there was plenty of water running through the motor. I felt the water and it was the normal temperature. I shut off the motor and checked the oil reserve, which I had just filled to capacity, and there was no change. I then started the motor again and began to run. This time I was able to get a few minutes of running before the alarm started going off. I again stopped and repeated the above process and again found everything to be within limits. The engine was burning oil as usual because the exhaust had the usual amount of smoke in it. I ran for the remainder of the trip with no alarm except when I got back to the dock. While the motor was at idle for just about a minute the alarm went off. I stopped the motor until it was time to trailer the boat, at which time the alarm did not sound. Any help would be appreciated.
