funny sound at full throttle

[MadeCoolCom]

MY 1980 Evinrude 60 HP 2 cylinders. It makes a funny sound at full throttle.<br />I will try to describe the sound.<br />It’s a constant sound and sounds a little like a electrical ark a close ark because it like a snap.<br />Snap after snap close together so it is solid sound.<br />I notice it at full throttle and seems to be getting worse. But it has been like this since I had the engine running. The engine seems to be running good accept for a little water leak in the bottom cylinder that’s not enough to effect the engine running or starting. It just a little steam. But I don’t think that the little steam is associated with the sound problem. Anyone got any ideas what might be causing the sound problem. As you can this engine is pretty much rigged all it needs is some bubble gum in the right place to stop the snap snapping constant sound might be fixed.. Ha Ha!<br />Guys any help on the sound you give will help me think about it and give me some incentive to do some more fixing on it. But even if I leave alone I would like to figure out is causing this sound, just to know .

 

[R.Johnson]

Re: funny sound at full throttle

There should be no water leak's, or any snap, snapping sound's. You may have a problem here.

 

[rodbolt]

Re: funny sound at full throttle

carefully inspect the coils and HT leads<br /> arcing will sound like snapping. fix the water leak

 

[Solittle]

Re: funny sound at full throttle

I would chase the "little stream" before I chased the snapping. Where is it leaking? Have you done a compression check? What is the rpms at WOT?

 

[G DANE]

Re: funny sound at full throttle

My 35 HP Twin had a kind of arching sound at wot, too. For a long time I thought it would be reeds that were hearble. I discovered the sound would disappear, when pressing hood down against cowling, at wot while someone else was steering. There is a lot of vibrations on these and the rubber gaskes between hood and cosling gets tires over years. That is is your sound is the same. It was like arching and more hearable if I bent down in boat.

 

[MadeCoolCom]

Re: funny sound at full throttle

Ok thanks you all for the info. Seems that I needed to wake up my brain on this stuff. I know I have fixed them coils several times and fixed the wires from arching in there to. I fixed all wiring. But I should check it again. Even though runs good.<br />As far as the steam goes. Well I replaced the head gasket a while back and I was surprised of how little aluminum was left on the block the only thing that made a good seal on the head gasket was the cylinder sleeve which looked liked stainless or some type metal that would not corrode. The aluminum block was corroded real bad. Maybe one day I will replace the head gasket and think of the best way to try and fix the corrosion on the block. Which I think is pretty much beyond repair anyway.<br /><br />I will keep boat for short trips only. And never leave port without making sure that my kicker 3.5 hp backup kicker motor runs.<br /><br />Anyone that has the steam problem. This is what I do <br />When I stop the engine. To make sure no water is sitting in the cylinder I would hold the kill switch and then turn the key so that the engine would spin but not start so than any water in there would get flushed out. It seem to help when I wanted to start my engine.

 

[G DANE]

Re: funny sound at full throttle

The corroded block is a bad thing. Rare on those, but common here on the pre 1974 20-25 HP's. Hard to fix, it will not seal properly only on the sleeve edge, which is cast iron. Only fix I ever saw that worked was removing a ring of the corroded material with a tool and to set a turned aluminium ring on outher side of sleeve in JB weld or similar. Takes a lot of machining, finding another block is easyer. Still, your arching sound might be hood.