1981 Evinrude 35

[Lubosleftboot]

Hi

Just serviced this motor and have ran it in a barrel to make sure the new impeller is OK and all appears to be alright.Here is a link to the motor running my question is does the engine sound OK to a more experienced ear?I reckon I can hear a wee knock but I am not sure.What do you guys reckon?

Link http://www.youtube.com/watch?v=jrBx2w9SzGc


Cheers LLB8)

 

[steelespike]

Re: 1981 Evinrude 35

It does sound like a tapping noise.
take the cover off and find a long screwdriver let it idle use the screw driver like a stethescope and listen all over the powerhead to find the sound.
Could even be an exhaust sound.Ive heard cars sound like a tapping valve and it was an exhaust leak.
On a 4 stroke if you unhook the plug it will make the rod talk up.Also when under a load the rod will be quieter as when you throttle up in neutral then as it reaches speed it will get louder.not sure about a 2 stroke.
Yours sounded quieter at apeed.

 

[muskrat]

Re: 1981 Evinrude 35

rans like a old 35hp,run it...

 

[emdsapmgr]

Re: 1981 Evinrude 35

Your engine sounds a lot like my 79 35 hp engine. Over the years, mine developed a definite knocking sound which was more audible at idle. It had great compression and ran OK. After 20 years of great service, I decided to tear it down for a look. Found that the upper crank bearing was failing-it was loose on the shaft. As the crank assembly turned, it would wobble in the bearing, causing the knocking sound. This was a typical failure mode with the 25/35 engines of this vintage. As the crank "wobbles" in the bearing, it also destroys the upper crank seal (causing an upper cylinder crankcase leak) which can additionally cause idling and starting problems. While I would not say that any catastrophic failure was imminent, my solution was to replace the upper crank bearing and it's seal. Took care of the knock and now starts and idles better. I was not able to detect this problem without the teardown. Good luck.