So I have a 83 40 mariner Yamaha engine. It runs rough and weak on and off from idle to plane. On Plane it runs smooth. it only does this sometimes and there seems to be no pattern to it and after planed it smooths out. Both cylinders are firing I pulled wires today while it was doing it. Both...
Very random issue losing spark to single cylinder. Very random happens maybe twice a day. It has a pulser Yamaha type ignition. It seems to not do it at a idle or at high throttle seems to always do it right above no wake speed. Also have never been able to duplicate this on a hose or in a tank...
