runs rough

[Walter]

I have a 1985? 115hp evinrude. It is running rough. I have replaced gas with new. I have changed spark plugs helps for a bit but then still runs rough. I did notice that plug wires has a split near boot cover on 2 plugs could that be the problem?

Also added gas stablelizer ran 6 gals still skips at full speed .

Thanks

Walter

[boats.net]

Could be the plug wires, if they are split then probably needs to be replaced. Could be dirty carbs.

[Walter]

I replaced wires. cleaned carb, I also replace one coil, still runs bad. any other info to help it run? I think it is electrical problem.

Thanks

Walter

[jtmurrow]

I just bought a 81 115 Hp evinrude and its doing the same thing, i am going to try a new fule pump. they say if the diaphragm is cracked or split it will give the same symptons you have... good luck

[andypanda]

I decarbed my '97 150 last year (for the first time) and it is runnin a little smoother. You may want to give it a try. Otherwise with the age of that engine it likely needs a carb rebuild. How did you "clean" the carbs?

To decarb - pick up a bottle of Seafoam - at any auto parts store - use a clean 5 gallon gas can add whole can of seafoam and fill with gas and proper amount of oil. Disconnect fuel line on the tank side of primer bulb and attach a 2 foot or so piece of fuel line - from any boat parts store. Dunk the fuel line into the mixture of sea foam and fuel and start engine - make sure you have a water supply connected to the motor - and run for 15 minutes drawing the solution into the motor. She will smoke like a chimnea but dont worry - that's the carbon and sea foam burning off. Shut her down and let her sit an hour. Restart and run 15 mins again- dont forget the water - Do this 4 or 5 times until she stops smoking or until the solution is used up.. Reconnect fuel line and the job is complete.
I believe this is called Dunk's method if you feel the need to google it for a second opinion.
Good luck skip.