Unseized Outboard

Dec 11, 2015
319
Hunter 25 Plymouth
I recently pulled up to my mooring, tied up, turned off my outboard and everything was great. I came back two weeks later and my outboard was seized and my radio dead. Originally I thought of lightning given both my radio and engine were not working but I think it was simply a coincidence. Bought a new radio, (the old one was 40 years old anyway) and brought my outboard home to work on. I sprayed all forms of release agents into the valves however the best was Marvel Mystery Oil. After several hours of using a ratchet to move the pistons, they became loose and then moved sufficiently. There must be compression as most of the Marvel came shooting out of the valve. I placed the pull cord back and placed it back on my boat to start. No luck starting and the pull cord now makes a noise as if I placed cards in my bikes spokes! Any wisdom, experience, suggestions appreciated...
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
If you also don't have spark, then a lightening strike would seem more likely.

If you tell us what kind of motor it is, you might get better quality responses.
 
Last edited:
Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Make sure you got the oil out of the cylinders.
Spark, fuel, and air. Make sure you are getting all three. Did you shoot some starter fluid in the carb when starting it to make sure it was getting fuel? Check the spark plug to see if it is wet after pulling the cord? Check for spark at the plug or wire. I had an old evinrude 4 that got seized, and Marvel Mystery Oil freed it up. It started after a while. I do not recall if I replaced the plug. Being I was a kid, I imagine I just cleaned it a few times til all the oil cycled through.
 
Dec 11, 2015
319
Hunter 25 Plymouth
Make sure you got the oil out of the cylinders.
Spark, fuel, and air. Make sure you are getting all three. Did you shoot some starter fluid in the carb when starting it to make sure it was getting fuel? Check the spark plug to see if it is wet after pulling the cord? Check for spark at the plug or wire. I had an old evinrude 4 that got seized, and Marvel Mystery Oil freed it up. It started after a while. I do not recall if I replaced the plug. Being I was a kid, I imagine I just cleaned it a few times til all the oil cycled through.
Yes I did spray starting fuel however not surprized if it's still wet from oil in the valves. Any suggestions to clean the valves out?
 
Jan 11, 2014
13,993
Sabre 362 113 Fair Haven, NY
Yes I did spray starting fuel however not surprized if it's still wet from oil in the valves. Any suggestions to clean the valves out?
Try removing the spark plugs and then repeated pull the cord with no fuel in the system. This will force air in and out of the cylinders which may help dry them out. Leave the choke off to allow as much air as possible into the cylinders.
 
Mar 29, 2015
69
MacGregor 25 trailer sailer
My first step would be to verify compression on both/all cylinders. Without that nothing will help. Ticking sound could be cracked/ broken rings or valvetrain issues on a 4stroke.
 
Dec 11, 2015
319
Hunter 25 Plymouth
My first step would be to verify compression on both/all cylinders. Without that nothing will help. Ticking sound could be cracked/ broken rings or valvetrain issues on a 4stroke.
I feel that the noise has to do with the pull cord assembly. I'm wondering if I installed it incorrectly.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
In the past I have hosed out oil with starting fluid. Carb cleaner will also work. Don't use too much or let it set in the cylinders too long. You don't want it to run past the rings and thin the motor oil. Pull the plugs out, spray it directly into the cylinders and start pulling the rope fast. This should eject oil/solvent from the plug holes. Put in new plugs and try starting it again.
All this assumes you have spark and compression.

All engines need 3 things to start, compression, fuel, and ignition. If any one is missing it isn't going to start. Oil on the plugs eliminates ignition.
Ken