Bought a nice looking 1965 Merc 650 two years ago and have hardly ever taken it out without breaking down. Something different each time. I have had engine completely rebuilt, rebuilt fuel pumps, replaced distributor/magneto. It ran okay for one short outing. I invited a friend on a 60 mile trip and motor stopped a half mile from house. Restarted okay but couldn't get much speed out of it. Boat will usually run around 28-29 mph. Water was choppy and boat is 17 foot cruiser. I throttled back just a bit and the speed dropped to around 10 mph. Slowly built up to 15 mph which was comfortable in the chop but I was at full throttle. Ran for a couple of miles and speed began to increase over 24 mph so I had to throttle back just a smidgen and it dropped to 10 mph. It repeated this for 15 miles and I gave up and turned around and came home. I checked fuel getting to carbs and filters were clean. Any thoughts before I unbolt and send my $4,000 motor to the bottom?
