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Ear muffs left on!!! What have I done!?

T

Trogsie

New member
Hi there, being quite new to this whole biz, I have made the fatal mistake of taking my boat out last night and had forgotten to take the ear muffs off!
About one and a half kms out the controls horn sounded , I looked around, smoke was coming out of the motor and it came to a dying stop!
I realized immediately and called my self F%$king idiot... dived in and ripped off the muffs.
half an hour later (after it had cooled down) we tried to start it again... not a hope in hell.
We were towed in by a nice bloke and I'm left with the responsibility of figuring out just how much I have ruined the donk. :(

It is a 1974 - 75 Evinrude 50 and it was my uncles in pristine condition with only about 10 hours run. The mech told me it was virtually new when he tuned it and couldn't believe it.
Any suggestions would be great! I'm very handy with a car but I am a novice when it comes to outboards! The fly wheel moves fine and the piston moves up and down and seems to have compression, so it hasn't seized but flywheel moving by hand sounds bad :(
It was perfect and I'll be very dissapointed if I've cooked it :(

Any suggestions would be great! I'm very handy with a car but I am a novice when it comes to outboards!

Help! Cheers
 
You said it yourself----you cooked it. It would be a very safe bet that you scored the piston skirts and maybe the cylinders. In any case, it needs to be torn down and all exhaust gaskets replaced. You can see the piston skirts when you get the exhaust covers off.

You probably also melted the water pump.
 
Curious, as soon as the warning horn sounded (it sounds before the engine is hot enough to overheat... Why didn't you shut it down then?
 
It has been my experience over and over again that if there is NO water flowing and you are running at any speed at all, it will burn up before the horn ever sounds. If it does sound. They usually don't. The piston skirts melt before the cylinder block and head get hot enough to close the horn switch. Then it sits there and smokes all the paint off and melt all the wires. My oh my, how many powerheads have I rebuilt back in the late '60s early '70s where there was no water flow because of a sudden spun hub in the impeller. The customer always insisted the horn never sounded.
 
fdrgator said:
It has been my experience over and over again that if there is NO water flowing and you are running at any speed at all, it will burn up before the horn ever sounds.
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That's never been my experience. In my years with OMC, starting in 1960, a boater picking up a plastic bag would also have the water supply eliminated immediately... and the warning horn has always sounded before encountering the destruction that the poster has described here. Actually, there was never any visible damage... raised the engine, the bag drifed away, the boater continued on with his day. However, upon my advice, he would examine the water pump and usually replace a somewhat distorted impeller at the minimum.
 
I said to my myself the motor sound a little different and looked around I saw that smoke was bellowing out.
The horn sounded as soon as I touched the control, as I powered down to shut it off, the horn beeped once once again then continuously.
When I got it back in to neutral , the motor slowed it's unhealthy sounding idle and stalled itself just before I turned the key.
 
I said to my myself the motor sound a little different and looked around I saw that smoke was bellowing out.
The horn sounded as soon as I touched the control, as I powered down to shut it off, the horn beeped once once again then continuously.
When I got it back in to neutral , the motor slowed it's unhealthy sounding idle and stalled itself just before I turned the key.
 
joereeves said:
That's never been my experience. In my years with OMC, starting in 1960, a boater picking up a plastic bag would also have the water supply eliminated immediately... and the warning horn has always sounded before encountering the destruction that the poster has described here. Actually, there was never any visible damage... raised the engine, the bag drifed away, the boater continued on with his day. However, upon my advice, he would examine the water pump and usually replace a somewhat distorted impeller at the minimum.
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And I highly respect you and your experience. I also find it remarkable that we both are in Florida and have experienced such different things. We had a virtual epidemic of spun water pump impellers and other guys seem to know nothing about it ever happening. Evinrude even sent their service rep to investigate why we had so many warranty claims for fried powerheads.
 
kimcrwbr1 said:
I have to ask you did mix the fuel 50:1 with outboard specific two stroke oil correct?
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Yes, it was 50 to 1 . 20 litres a added maybe a bit over 100mls , a little over wont hurt the engine will it? I'm sure the problem was that I ran it pretty hard with zero water for 20 minutes.
 
Trogsie said:
Yes, it was 50 to 1 . 20 litres a added maybe a bit over 100mls , a little over wont hurt the engine will it? I'm sure the problem was that I ran it pretty hard with zero water for 20 minutes.
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I am not sure what you are saying here. Perhaps you are saying that you added 100 ml in addition to the 50:1 ratio. But to be clear, 50:1 is 400 ml of oil in 20 litres of gas.
 
kimcrwbr1 said:
If that is the case and you run it at 200:1 your better off just looking for a different powerhead you likely destroyed the crank as well. If you added 500 ml then the engine may be serviceable with a little work. You need to disassemble it to see what it needs.
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Gee I hope not I thought it was mixed correctly , my brother mixed it a little over 300ml to 20litre he said the bottle only had 300 left in it , I just bought a new bottle , added another 100 mills of the same stuff to top it up before we went out. I'm sure it over heated due to the muffs being on.
I'm going to check compression on Monday, does anybody know what compression numbers I'm looking for for these 74 evinrudes? And if compression is good and there is no scoring I'll chuck in a new water pump as I've likely killed it.
Also, where would I find gaskets, is there somewhere on line? Appreciate everyone's feedback thanks! I'm pretty pissed off with myself, I just want to get it going and hoping I haven't done too much damage. It was going beautifully so it's bloody heart breaking if I've completely F^&ked it from such a stupid mistake!
Somebody tell me it should be ok! haha!
 
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Sorry, I don't know for sure what is normal compression on that motor, guessing around 120psi (???)
You are at one of the best on-line parts stores there is, marineengine.com
 
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