1968 20 hp Running Rough

[viciousfishes]

Hey guys,

Whenever I take my boat out it cranks up the first try and it idles and runs flawlessly PROIR to me going to wide open throttle. Once I start going fast it runs perfectly but then Ill slow back down and it runs rough as hell. I have no idea what this could be. Maybe Im putting too much oil in the gas and fouling a plug? I just dont know where to begin.

Thanks in advance

 

[mars bar]

Re: 1968 20 hp Running Rough

How are your plugs? maybe ones breaking down. Try mixing your fuel in a jerry can, then adding it to your tank. Sometimes people add to much oil to the fuel and it goes from fill up to fill up. Is there lots of smoke from the exhaust. Could be a coil heating up?

 

[viciousfishes]

Re: 1968 20 hp Running Rough

Im going to get new spark plugs, why not. And I know its not the coils because I just replaced both of them. My magneto is immaculate. It might be as simple as too much oil. Or maybe water in the gas? I dont know

 

[mars bar]

Re: 1968 20 hp Running Rough

Water in the gas is a big thing in performance. Carbs are clean and set right.