Oh boy, have I got a crack...

jcw74801

Seaman Apprentice
Joined
Feb 29, 2008
Messages
32
I bought a good fishing boat so cheap that the engine was basically free. The owner, a fishing guide, had the powerhead rebuilt by a reputable shop. Not too long afterward something went bang and the block was cracked. I don't think I got the whole story but I was able to buy the boat and motor at a time when I could not afford a boat or a motor.

Since the motor continued to run strong with good compression I decided to run it and keep an eye on it. It's just a weekend fishing boat used on a local lake. Well, 5 years later and it still runs strong and compression is still good. It has, however, developed a knock. It's finally time to open her up and see what's what.

The visible portion of the crack is at the #1 intake. Then it goes up and over the top, disappearing under the flywheel. Today I pulled the intake and flywheel. The crack does penetrate the #1 intake. Then it goes all the way across the front of the block to the other side.

I am assuming that #1 has been running lean. What I can see of the cyl. wall through the intake seems to indicate just that. Hopefully it also explains the knock.

In the pics I highlighted the crack for visibility. The cylinder pics are through the intake with the piston as high as it will go. The block is upside down on a stand. I think you can tell which of the two is the bad one :)

I almost hate to ask, but does anyone think I could get this block repaired?

What are my options?

This is my first outboard, to own or repair, and I'm still a little shocked at how much the parts cost. I don't want to try and piece this thing back together to find out I could have bought a rebuilt powerhead for less. Or a whole used engine.

Not sure which direction to go. Thanks for your input. This is a 1996 J150EXEDB.

2012.mar05.boat.crack2.jpg

2012.mar05.boat.crack3.jpg

2012.mar05.boat.crack4.jpg

2012.mar05.cyl.wall.jpg

2012.mar05.cyl.wall2.jpg
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Oh boy, have I got a crack...

You need a new block or a rebuilt p/h. I think water got in it.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: Oh boy, have I got a crack...

My opinion, that powerhead is done.
3 grand for a rebuilt one, but that is much cheaper than a new motor if you are otherwise satisfied with the motor.
 

Haffiman

Commander
Joined
Dec 17, 2009
Messages
2,454
Re: Oh boy, have I got a crack...

I would not have written off that block until it has been completely dismantled and if possible checked out the crack on the inside. I good welder might work wonder.
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Oh boy, have I got a crack...

Just say no to crack. Yikes that's ugly
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Re: Oh boy, have I got a crack...

That a fairly common crack on the 60? engine as it has cracked in the glue line where the styrofoam mold was put together. It will crack thru into #1 cylinder and leak water into cylinder causing a knock at around 3500 rpm and eventually failure. Find a block as this is not repairable. Make sure you get the correct year replacement block as there where a couple of crankshaft and end cap differences. and do not do any machine work to replacement block till it is pressure tested first to see if its a internal leaker!!!!
 

jcw74801

Seaman Apprentice
Joined
Feb 29, 2008
Messages
32
Re: Oh boy, have I got a crack...

Great info. I didn't realize this design had issues. Boobie, you hit the nail right on the head. Water in #1 cyl. Going from the thermostat, across two o-rings, and into the cylinder. See the pics. And now I learn that the crack could also be watering the same cylinder. Thanks Faztbullet!

A rebuilt powerhead is starting to sound better all the time. I'll get a good block, heads, and crankshaft that have all been tested and machined, plus new pistons, rings, bearings and seals.

Should I be pulling the heads for inspection and changing o-rings on a regular basis with this motor?

The last pic shows one of the good pistons. The carbon is soft and comes off pretty easy. I did a decarb last year. Is a decarb supposed to clean the pistons or is it just to prevent a ridge on the cly. wall that can break a ring? The 5 good cylinders are beautiful.

Thanks for the help guys, including Haffiman from Malaysia! Here's some pics for your viewing pleasure:
2012.mar06.cyl.head3.jpg 2012.mar06.cyl.head2.jpg
2012.mar06.cyl.head.jpg 2012.mar06.cyl.head4.jpg
2012.mar06.cyl.head5.jpg
 
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