I have had this problem for the last couple years, my motor did not have any power wot, I could go up the lake and stop {turn it off} for a few minutes start it back up and it would scare you it would run so fast...I could not find the problem cause the time it would take to change a plug the problem would disappear...until now...{stoping and waiting makes no difference}I have check plugs by taking the plug wires off while running one at a time, with one not making a difference in the sound of the engine when I took off the wire, the other three would just about cause the engine to stall I switched out the ignitions coils the same way with the same cylinder not firing..My question is could it be the power pack and if so are they anyway a beginner like me could check this without buying expensive test tools...I have a manuel and used this to help change the impeller and check the thermostats and all are OK..just this nagging problem with cylinder not firing....HELP