1978 evenrude 115hp won't top out

[wd9373]

The motor fires right up, idles great, when I take off I cant get everything out of the motor, usually about 4000 rpm, and periodically after it is trimmed up alot, it will go full throttle, but not often. Also uses a ton of gas.<br /><br />I have got a few answers, I have new plugs in it and the ones I replace were only used a couple of times and fowled. when I took the four old plugs out they were all wet.

 

[DJ]

Re: 1978 evenrude 115hp won't top out

willfish,<br /><br />More than likely, you are only running on 3 cylinders when your top rpm is 4000.<br /><br />Take a good look at your spark plugs, they may help you ID which cylinder is the offender.<br /><br />This could be carb. trouble or spark. It is difficult to tell since the rpms eventually come back.

 

[Cricket Too]

Re: 1978 evenrude 115hp won't top out

The reason the RPM's come back when you trim off is because there is less resistance on the motor because it is coming more out of the water. But there is most likely a cylinder prob. or a carb prob.

 

[ajp]

Re: 1978 evenrude 115hp won't top out

Maybe that is all the go power it has. Does the tach work correctly. Those of v4s use a ton of gas.<br /><br />My 1969 V4 uses alot of gas and according to the speedo on my 1969 deckboat, only shows about 28 mph max. It does sound like I am getting all it has. No tach, just a wound up motor. <br /><br />If you are only hitting on 3 cyl, I don't think you would even get 4000 rpms. You might get 10mph.