115 hp Evinrude No power

I am grateful for any help on this. I have a 79 model 115 hp V4. The problem is this motor has set for 2 yrs. I am trying to get it back on the lake. This thing runs great when the muffs are hooked up and when throttled it sounds great and smooth. While running I will pull each plug wire individually and it will cause the motor to spit and sputter until the wire is connected again. This happens on every cylinder but 1. On one cylinder it does not make any difference whether the wire is hooked up or not. I have checked the spark and it is fine. Plug is fine, 115 psi compression. Carbs have been built.<br />I put this motor on a 18" procraft bass boat but could not get the boat over 18 to 20 mph.It has 13x19 prop. Please advise. Thanks in advance.

Re: 115 hp Evinrude No power

I had the same problem with an motor the same as yours. I would first switch one of the other coils for the one on the cylinder that is dead. Second if that doesn't work interchange the power packs left and right. If still no change check for bad fuel pump. If the cylinder is on the port side bottom the fuel pump operates on presure cange in crankcase for that cylinder. If it's another cylinder check that a fuel line to the carbs are not kinked (this was my problem). <br />I rebuilt my carbs twice and make sure to take out the pressed in plugs before cleaning. Also, run small wire through the very small holes in the bottom of the carb throat. I think there are three holes in each of the two throats.<br /><br />Sherm

Re: 115 hp Evinrude No power

Have you tried running the engine on the lake with the top off? Sometimes the spark plug boots short across to the hood latches.<br /><br />TMD

Re: 115 hp Evinrude No power

Thanks for all the advise. I pulled the carbs again, sprayed them out and cleaned all the small holes. I really was not thinking it would help but did it anyway. Changed the plugs again and went to the lake. This time it ran great. This 18 footer will run around 48mph with the 115hp. Very satisfied. When I got home I did start the motor up and pull the plug and still it does not make any difference in how the motor idles. I am convinced that this cylinder is firing when the wires are hooked up and the motor is running. I just can not explain the no change when the plug is pulled and it is idling.<br />Thanks again.

Re: 115 hp Evinrude No power

Hi,<br /><br />something to consider.<br /><br />If there is a clean break in the conducting portion of the spark plug lead (which will not be visible to the eye) there will not be sufficient voltage at idling rev's to bridge the electrical gap. This manifests in the no change in the rev's at idling with the lead on or off.<br /><br />At higher revs's the voltage increases and is often enough to bridge the gap, consequently the plug fires and the engine runs O.K.<br /><br />Cheers<br />Andrew

Re: 115 hp Evinrude No power

Also consider a new set of plug wires & plugs.