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Morten amp Joe we found the problem Johnson 1101987

D

doug_bryant

Regular Contributor
"Well, guys we broke the power

"Well, guys we broke the power head down Saturday night and found a few problems. The first glaring problem was that at sometime in the engines past it looks like it was severely over heated. So much so that it warped and broke 1 of the exhaust filler blocks. The next problem that we found was that the other filler block adjacent to the cylinder that went bad had been letting salt water seep past onto the piston. The under side of this block was heavily salted. Finally, the crankshaft was cracked at the opposite end from the flywheel. The crank looks like it had been cracked for a while as it was black inside where the pieces fell out during disassembly. The good news I guess is that the pistons and the cylinders are original spec so it hasn't been bored out in the past. I will post some photos in a couple of minutes. My chip reader is acting up."
 
"Here are some photos.
<[img]

"Here are some photos.
62134.jpg
62135.jpg
"
 
"I do not quite want to kill Y

"I do not quite want to kill Your 'happiness', but so far I would say we are still in the 'chicken and egg' phase, except for perhaps one part: The cranck shaft dammage.
Filler blocks as shown after such a dammage, is normal, they just melts down like the pistons. As the fastening screw goes into the water channel, it will leak water into the exhaust chamber when engine is stopped and start corrosion.
At the moment I'm more into that the lower cranck shaft seal may have been dammaged, then reducing the cranck case vacum/pressure -leaned out/reduced the fuel/air mix - which again has lead to the rest of the dammages. I have to admit that this should mainly have affected cyl 4 and not 3, but still there are more to tear down.
Good thing the block may be saved, sad about the crank."
 
"Yes, the block is ok. The cyl

"Yes, the block is ok. The cylinder sleeves are available from Sierra and I am going to find someone who can remove the old sleeve and install the new one. I have already located another crankshaft. I am going to repair it and sell it. I have designs on a newer motor, one with a warranty."
 
"Doug,

I would just bore th

"Doug,

I would just bore the damaged cylinder; it seemed like the other cylinders were not damaged. The filler blocks are frequently damaged; not really a sign of overheating, but take a careful look at the exhaust ports before you decide what to do. I would expect to see some pitting there.

I have never seen a crank broken like that before, but I don't think it would affect crankcase pressure. The seals (rings) between each compartment isolate the fuel intake for each cylinder. It could have impact on the oil recirculation though which could be disasterous.

Send the cylinder heads to the machinist along with the block, and have them checked out. I still think you had a leaky head gasket there.

Tony"
 
The crank breaks like that whe

The crank breaks like that when the block is not removed properly .Best to remove the lower unit when a block does not come up evenly.A thinwall sleeve and new larger bore seal (research required ) would take care of the crank problem
 
My brother and I have been spe

My brother and I have been speculating that it is very possible that the power head has been removed in the past. We are basing this on how easily the block came apart and by the look of the 3 other pistons. The good pistons look almost brand new. The problem has been resolved. I bought a 2005 Yamaha 115 2 stroke this morning and my Johnson will be rebuilt and sold to pay for a new kicker motor.
 
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