Frozen Johnson 3 hp 1960

jaxx

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I have a frozen Johnson 3 hp Sea-Horse 1960, Model JW16. What parts are most likely frozen? What would be the best way to try to free it up? Thanks.
 

Chinewalker

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Re: Frozen Johnson 3 hp 1960

There are three spots the motor can freeze at (or any combination of the three).

Most common is the pistons are stuck. Can be caused when the motor is inverted shortly after running, allowing water into the cylinders. Piston rings rust to the cylinder walls. Can also be caused if the motor has had a catastrophic failure - lack of oil, overheating, etc.

Second most common is water ingestion into the crankcase, rusting the crankshaft. Can be caused by water in the gas, submersion, etc. Can also be caused by catastrophic failure - lack of oil in gas, etc.

Third most common is water in the lower unit, rusting the gears and shafts.

I'd start by pulling the lower unit to easily dismiss that as a possibility. Then pull the cylinder head to take a look there. DO NOT attempt to free the motor with torque on the flywheel. That motor has aluminum rods and they WILL bend/break with excessive force. If the powerhead is stuck, pull it apart to find where. Don't try to "free it up". Even if you do get it unstuck with penetrating oil or the like, there's a good chance some bearing surfaces are now rough due to rust and will wear prematurely. Your motor has "plain bearings" which can't take a whole lot of abuse. If the rust is localized and not deep in the surfaces, you might be able to polish them out with emory cloth.
 

wilde1j

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Re: Frozen Johnson 3 hp 1960

If frozen while stored upright, may not have been correctly fogged prior to storage. If so, rings probably rusted to cylinder bores. Put in a position so spark plugs holes face upward and pour some ATF in each cylinder ... let sit for 4 to 7 days, then try rocking flywheel to break free. I had a 5 HP Royal many years ago, and in spite of proper fogging, the rings would rust to the cylinder walls over one winter stored indoors and upright. This happened almost every year!
 

jaxx

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May 28, 2010
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Re: Frozen Johnson 3 hp 1960

Thanks to Chinewalker and Wilde1j for their quick responses. I will first try some ATF as Wilde1j suggests (even though Chinewalker recommends against it) because I have no experience disassembling an outboard. I had tried some liquid wrench in the cylinders to no effect.

I have purchased the Seloc repair manual that covers this engine but find it hard to follow.
 

Chinewalker

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Re: Frozen Johnson 3 hp 1960

As I noted, if you try to free it up that way, go VERY easy on the rocking motion, as those rods will not take much brute force.
 
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