1989 70hp evinrude high rpms

[mandyman1345]

I recently took out the boat and as I was going across the lake then I believe that it is the over heat horn went off and shut the engine down. I started it back up and it started and would only run at 1500 to 2000 rpms as it states in the manuel to protect the engine. At first I thought maybe I got into some weeds, but I was in the middle of the lake at the time. I put it in reverse to clear out any thing in the intake filters. I slowly got back to the dock and then brought it to a local repair shop. I got it back and they stated that they could not find anything wrong. The horn was working fine and they did a compr check and said it was okay. I took it back out to the lake and now the rpms at idle are just under 2000rpms and at full throttle it is at just under 8000 which is as high as the gauge will go. The engine seems to be running fine. It has a slight rough idle which it has had. The engine seems to sound fine except the tack is slowing 2000 rpms more than it should at any speed. What I am trying to say is that when I am at full throttle it shows just under 8000 rpms the engine sounds fine and not sounding like it could blow at any moment. Any suggestion would be appreciated.

 

[pmat1]

Re: 1989 70hp evinrude high rpms

The WOT for that engine is 6500; your tach may be off.

 

[mandyman1345]

Re: 1989 70hp evinrude high rpms

Thats what I was thinking. As the engine has got older I have notice the rpms have gone up on the tack with no notice of engine sound going up.

 

[Daviet]

Re: 1989 70hp evinrude high rpms

Do you have access to a hand held tac? Maybe the shop that checked out your engine has one? You could compare the two and see if your tac shelled out on you.

 

[pmat1]

Re: 1989 70hp evinrude high rpms

Definitley check the tach, 8000 and the engine would surely not last long.
As for it not running right, wait for the pros respond, im little help.

 

[mandyman1345]

Re: 1989 70hp evinrude high rpms

Thanks petty Officer.

 

[mandyman1345]

Re: 1989 70hp evinrude high rpms

Thanks again pmat1.

 

[mandyman1345]

Re: 1989 70hp evinrude high rpms

Anybody else have any input on the high rpms or the reason that the overheat alarm went off. I did notice that the motor is pumping water at a solid flow except in the past it was stronger to the touch.

 

[Daviet]

Re: 1989 70hp evinrude high rpms

Could you have wrapped something around the intake on the lower unit that fell off when you stopped. Just thinkin.