1978 johnson 55hp Huge HOLE in BLOCK Help!

TrickyRicky

Seaman Apprentice
Joined
Jul 17, 2012
Messages
37
I just got a used boat in a trade 16' aluminum Lowe .
Has a 1978 Johnson 55hp model 55EL78S
The engine wiring harness is completely gone/ rotted out. I ordered a new one already from CDI electronics.
I did a compression test 130psi both cylinders. OK ? Seems low but at least even.

Here is a huge problem I found while replacing the fuel inlet hose to the pump. The front engine bolt (one of 4 rubber mounts)is broken off flush. Next, I found a chunk of aluminum sitting beside the block. After an oh ship moment, I started looking for a missing chunk. I noticed an area that the repaint on the Block looked funny. After some probing and picking removing epoxy I found a big hole in the lower intake runner. There was marine tex for the patch with a piece of thin sheet metal on top and another thin coat of marine tex to conceal it.
Not sure why a hole would be there. There is no water jacket in that area. It also seems that the upper intake has been patched the same way. I have not even started the engine so I have no idea if it will run. I plan to REPATCH the marine tex and install the harness next week when I get it. I really don't know much about this engine but was told it ran good before it sat for the last 6 years. I did take the carbs off and inspect they were very clean.
Is there a design flaw that causes cracks in that area? Should I look for another powerhead for it or just get a different outboard? Anybody know of a salvage yard I may find a used 78 complete or powerhead? Advise please I am a decent auto/atv mechanic but have only had 2 other boats. Did see powerhead on Flebay but one back mount is broken. Thanks
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Post a clear pic of the problem, please.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,224
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

You know the routine: patch it up and find some sucker and sell it to him. That's what the last guy did. Got morals or integrity?

I think there is a sticky on this forum listing scrap yards
 

TrickyRicky

Seaman Apprentice
Joined
Jul 17, 2012
Messages
37
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Block hole 001.jpg Here she is in her holey glory! Ouch
 

TrickyRicky

Seaman Apprentice
Joined
Jul 17, 2012
Messages
37
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Thought I might see if one of you old salts may have a line on a 78 seahorse
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Looks like it threw a rod at one time or another. Next question would be, what's the crankshaft look like ??
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Look in the "Top Secret File" sticky at the top of the page, there is a list of salvage yards there, maybe one of them can help you out.
 

TrickyRicky

Seaman Apprentice
Joined
Jul 17, 2012
Messages
37
Re: 1978 johnson 55hp Huge HOLE in BLOCK Help!

Thanks for the Salvage list.
Are any other year powerheads interchangeable when I call around looking. Evinrude is interchangeable? Sorry not 100% sure
 
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