Re: 1974 Mercury 20HP Thunderbolt Ignition Problems
I had a 1970 20 HP and had the same problem. It was really a very simple fix. I had been having some difficulty with the kill switch and wound up pulling the wire off of one of the spark plugs to make it stop. Three hours later when I was showing the motor to a prospective buyer ( after assuring hi m that "the motor runs GREAT/always starts on the first or second pull") I wound up pulling that thing about 35 times and it finally started and ran like crap. When I had pulled the wire off the spark plug I had also loosened the wire going up to the coil which was hidden by the shroud. It only backed off about 3/16", but, that was enough. I pushed it back on and it started right up.......first pull.
I had a 1970 20 HP and had the same problem. It was really a very simple fix. I had been having some difficulty with the kill switch and wound up pulling the wire off of one of the spark plugs to make it stop. Three hours later when I was showing the motor to a prospective buyer ( after assuring hi m that "the motor runs GREAT/always starts on the first or second pull") I wound up pulling that thing about 35 times and it finally started and ran like crap. When I had pulled the wire off the spark plug I had also loosened the wire going up to the coil which was hidden by the shroud. It only backed off about 3/16", but, that was enough. I pushed it back on and it started right up.......first pull.