Seized cylinders

Kiwi Phil

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Jun 23, 2003
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2,182
Couldn't find anything in the search that answered my question.
Have a 1980 50hp Johnson that has been sitting in the shed for about 3+ yrs and John decided to check it.
He reckons the top cylinder rings are seized, so we squireted wd40 in it and could hear the 'squirting' out the prop at bottom. He believes the rings are seized with rust, and probably rust has made a hole too.
His suggestion is to sell it as-is for parts as cost to repair may exceed value of motor.
Before I proceed with that option, is there anything I should do first meaning:
can I free it, and if so, how?
is it repairable for a reasonable cost, or am I just wasting my time.
I don't actually have a need for it.
Cheers
Phillip
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
Messages
51,019
Re: Seized cylinders

well i would pull the head, could be the piston is in the exhaust stage. you can pull the exhaust and by pass covers. and 80 50hp running is still a good engine. if you part it out, you will get more for it, in parts, than in a whole motor. people looking for parts don't want to ship a complete motor for a lower unit.
 

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: Seized cylinders

Sometimes they barely stick and are easy to get loose. Other times they won't break loose no matter what you do. On the worst ones, antique motor collectors fit the sparkplug hole with a grease gun and pump grease in at pressure. Sometimes it works quickly and other times it takes days or weeks to finally budge the pistions while pumping everyday to keep pressure up.

On easier ones try turning the flywheel by using a spanish windlass for leverage (I've freed smaller motors with a large wrench on the flywheel nut - you may want to try this but remember it's a nut that may have to come off someday). Gently rock it back and forth. If that doesn't work use a heat gun and hot/cold cycle the pwrhd several times. This has worked for me and it's suprising how easy they can break loose with leverage. Three yrs sitting probably means it isn't stuck too hard so don't give up easily.


bp
 

Kiwi Phil

Commander
Joined
Jun 23, 2003
Messages
2,182
Re: Seized cylinders

Update:
We pulled the head. John, my worker tells me the pistons are ok, but power head is not. One half is smooth, the other isn't.
Then took side cover off and the rings are OK he believes.
One piston is 'in', the other 'out'. Everything seems fair there.
He believes it could be , I think he said, bearings.
There is absolutely NO movement.
He has put pressure on the wheel, everything, it is seized.
We have discussed it, and unless you guys have a brighter idea, John reckons sell it for parts, as the cost for parts and time may exceed the value of the motor.
Any suggestions or comments would be appreciated.
Cheers
Phillip
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Seized cylinders

Hold on before you give up. drop the lower unit, it could be froze up and not allowing the power head to turn. has he check the lower from water intrusion. a donor lower unit could put you back in business. if it isn't. it's already off to be sold.

you can look up the engine diagrams and parts list, at the link below, get a list of what he thinks you need. price it out. sell the parts will make more money than than sell the whole unit, people don't want to ship parts the don't need. starter, carbs & intake, exhaust cover, head, lower unit. etc. Ebay is a great market place for this kind of stuff.
http://www.evinrude.com/en-US/Accessories/Literature/
 
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