2000 Johnson 70 j70plsis

tkdrumr

Seaman Apprentice
Joined
Feb 9, 2016
Messages
33
I just picked up a 2000 Johnson 70 hp outboard from Marketplace. The seller was very clear, it overheated and one cylinder sleeve has rotated out of position. That's OK, I bought a short block the day before and wanted this for parts anyway. So, I decided to take it apart and split the block to see what it looks like.

Here is a picture of the middle cylinder - the one that rotated as you can see. There is what looks like a gouge on the end of the port. It almost looks like it was done in the machining. Any ideas what this is?

The only other damage I saw was the top cylinder was melted a bit and there was some aluminum on the wall. I'll get pictures of all three pistons and cylinders. I'm considering attempting to reposition the sleeve, run a hone, put in a new piston (I have one available), put it together and run compression and leak down tests on it.

20250103_173427.jpg
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,920
Someone cut that or came from factory like that. Sleeves are installed/straightened and block is drilled in middle of transfer port webbing. It is only drilled deep enough to dimple the sleeve and a set screw is installed and epoxied over
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,019
What item # is 350943 and on what parts page ?-----To me it looks like it was machined ( error ) and let go by inspection.----In 2000 there were issues with OMC as company was in trouble.
 

tkdrumr

Seaman Apprentice
Joined
Feb 9, 2016
Messages
33
What item # is 350943 and on what parts page ?-----To me it looks like it was machined ( error ) and let go by inspection.----In 2000 there were issues with OMC as company was in trouble.
When Faztbullet posted the comment about pinning the cylinder, I searched and found that item. Looking again, that part is in the exhaust housing. Your assessment is what I was also thinking.
 

tkdrumr

Seaman Apprentice
Joined
Feb 9, 2016
Messages
33
Someone cut that or came from factory like that. Sleeves are installed/straightened and block is drilled in middle of transfer port webbing. It is only drilled deep enough to dimple the sleeve and a set screw is installed and epoxied over
Thanks for the description. I picked up this entire outboard and controls for parts, so I'm not sure if I'll have the PH fixed, hold it, or sell it. Maybe I'll drop it off at a machine shop and have it assessed.
 
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