1991 Envinrude 40hp VRO will run at low speed, almost no power above idle

[davesc]

I have a 1991 Evinrude 40 Hp VRO. The water pump is fairly new. It will run good at idle but as soon as you give it any power it starts to die off but will keep running. At full power it will only go slightly over idle speed. It ran good for awhile the other day but started to lose power over a time period of an hour or so. I was only able to make it back to the dock at idle speed. Can anyone please give me an idea of what to check or replace? <br /><br />Thanks<br /><br />davesc

 

[JB]

Re: 1991 Envinrude 40hp VRO will run at low speed, almost no power above idle

Howdy, Dave.<br /><br />Chances are good that you are runnning on one cylinder. By disabling one spark plug at a time you can quickly find out if you have a dead one.<br /><br />If both cylinders are firing, check your fuel system for restrictions or air leaks, and check your fuel pump for good output.<br /><br />If you have a dead cylinder with good spark, you have a gummed up carb.<br /><br />Good luck.

 

[davesc]

Re: 1991 Envinrude 40hp VRO will run at low speed, almost no power above idle

Thanks for your help. I will try to look at your suggestions. I will post my results soon.<br /><br />davesc

 

[boates45]

Re: 1991 Envinrude 40hp VRO will run at low speed, almost no power above idle

I have a 94 50hp evinrude. Did the same thing to me 2 years ago. Thought I was sucking air or something, and was losing my prime when it did this. I too had to idle back to dock. Took it in, and it was the VRO pump. Put a new one in, and has ran fine ever since.