[Old Crow]

Model 50ELHPT45
Serial 0G315627
I'm having problems with the motor running rough from idle to 1/2 throttle. I first thought it was an ignition related problem because it drops a cylinder or two then they will fire back up. All for plugs had good spark when I checked. I replaced the spark plugs and found when checking the old plugs the number one cylinder is black with a dry soot (not wet and fouled) It is much different than the other three.

[mjlizana]

have same problem in 1989 90hp Top Cylinder is charred when looking thru plug hole, Did commpression test and test was ok..... poppet valve was busted on mine which gives water pressue extra flow to upper cylinder....still troubleshooting hope this helps sorry a year late