OK, here's the situation . . . <br /><br />83 50 HP Evinrude - sat out in weather for 4 yrs. Been cleaning - plugs, gas lines, carbs (pulled apart and sprayed lots of carb cleaner, but no rebuild), Seafoam in the gas tank (1 oz. to 1 gallon - 3 gallons), compression 155 & 160, what appears to...