1979 40 HP Evinrude

[sam johnson]

Just bought used 1979 Terry boat w 40 HP Evinrude. Boat not used for over a year. Finally got started. Idles rough. Ok power up to about 1/3 throttle. Above that forward motion actually decreases, w noticeable increase in vibration. Seller says new plugs and carb rework two years ago. I can function in my no water area but am not comfortable going out on main lake. Any ideas? Thanks, novice boat owner, Sam

[Elton Smith]

I own one of those.Sounds like the carbs need adjustment.What happens when an engine sets up is the gas in the carb evaporates and leaves the oil residue to gum up.Run some marine gas treatment in it before you put it in full service.