'77 Evinrude 140 engine noise

[dick reaves]

Recently at around 4000> RPM I started getting a noise, seems to be from the front section of the motor. This is a loud high pitched ringing sound, not the duller sound that I would expect from a bearing or rod. Dropping below 4000 stops the noise. I do my own auto repair but am new to outboards. The noise sounds a lot like a metal part left laying in the housing and rattling against the motor. I've looked and have about decided the last was wishful thinking. I have been hoping for one more outing before dropping the lower unit and overhauling the water pump. Any ideas welcome.

 

[R.Johnson]

Re: '77 Evinrude 140 engine noise

Check the oil in the gearcase. Find if it smell's like sulfur, or has a metallic shine.

 

[Chinewalker]

Re: '77 Evinrude 140 engine noise

I've seen this on several of the V4s - ended up being the cowling latch coming loose and vibrating at certain RPM. Have someone hold their hand on the latch while you're running and see if they can make the noise go away...
- Scott

 

[clint]

'77 Evinrude 140 engine noise

It does sound like a vibration problem. I wouldnt think of it being internal. Cowel latches or check the bottom latch points. There are small rubber boots that wear away and making this noise.
Clint

 

[dick reaves]

Re: '77 Evinrude 140 engine noise

I've checked the latches and found them to be tight. Clint, I looked at the boots and all three have lost enough to have one side of bare metal exposed. I'll repair and let you know at a later date it you applied the hammer to the old nail head.
****

 

[clint]

'77 Evinrude 140 engine noise

My 1979 140 had the same noise. I went on to buy 3 new rubber boots for less than $5.00 it solved the noise problem from the vibration metal to metal at these 3 points.
Clint