I have a 2-stroke, 3 cylinder, 60 hp Mercury outboard, circa mid-80's. The motor has always run great until the last 4 or 5 times out. The motor starts up right away but only fires on two cylinders. Idling the motor, or driving the boat for awhile doesn't clear up the problem. But, if I pull the top plug, which always looks okay, and put it back in, the motor runs fine the rest of the day. (I haven't tried this with the other plugs.) I've put new plugs in but the problem remains the same. Maybe it's a coincidence, but the problem seems to have started now that cold weather has set in.
