1969 25hp Evinrude overheated wouldn’t restart

[BlackoutBill21]

i Just posted about this outboard and what happened. But I just did a compression test and have a dead (58psi) top cylinder. 120 on the bottom

Question is where do I look first? Head gasket? Or did I fry the piston rings?? It was pumping water like a champ. I still don’t know why it overheated.

 

[boobie]

What's the compression on the bottom cylinder ??

 

[BlackoutBill21]

120

 

[Vintin]

Hopefully it is just the head gasket. Pulling the head is where you start and depending if you find ugliness inside or not, you decide where to go from there.

 

[BlackoutBill21]

Sounds good! Thank you

 

[jimmbo]

If you got it hot, the head may have warped too. Check it with a straight edge, length wise, cross wise, and diagonally. You might have to lap it using a very fine abrasive cloth/paper on a perfectly flat surface.
You may also want to pull the transfer passage cover to check the rings for tension, to see if the piston skirt is scuffed/scored. If the intake side of the skirt is scuffed/scored, the exhaust side is gonna be worse.

 

[BlackoutBill21]

Copy that I will do that too! Thanks guys

 

[BlackoutBill21]

Quick update... I got the head off!! Only broke 2 bolts!! I’m seriously excited cause it should have been all of them...soooo I’m assuming this motor is toast..

you guys tell me

 

[racerone]

The powerhead is worth about 11 cents / lb scrap.-----Lots of good used parts available for that powerhead if you have the patience to look.

 

[BlackoutBill21]

But the block is toast no? Why buy parts for a bad power head? I have the patience... that how i got it running in the first place...

 

[racerone]

The block is SCRAP.-----Lots of those motors were made.-----I picked up a parts motor a while back at a meet.------$25 was all.----So lots to be found if you have the patience to look.----A new motor with warranty is another option for you.

 

[BlackoutBill21]

Yeah that’s what I meant... I found all the parts for this and 15 other motors I’m working on... finding a cheap block is not. But t as it sits i clearly have no other option but to look

 

[54bobby]

Grab another one for 300 or so and keep yours for parts

 

[jimmbo]

From boat motor to boat anchor, in just a few seconds

 

[Chinewalker]

That damage is more than an overheat. It took time to get that much separation from the block casting and sleeves...

 

[BlackoutBill21]

chinewalker... yeah thats what i thought..

funny story you guys might enjoy. I bought a seized up 25 hp for the lower unit to throw this powerhead on originally...........TOTALLY forgot i still have the seized up power head!! I already have a 25 hp block! lol didnt put 2 & 2 together... gunna take the block apart and see how the cylinder walls are.. I might have enough parts between the two to restore the seized power head!.