1962 Sea King 15hp wont pull

I received a 1962 15hp 2 stoke outboard from a friend for free. He recently serviced the engined, cleaned components replaced sparkplugs etc. He had it running for a bit, came back the next day and it had seized up on him.

It isnt worth what it would cost a mechanic to perform diagnostics. I am not too motor savy and would like to use this to learn a bit, even if I never get it running. I am thinking since it wont pull, something in the engine itself has seized.

I guess my next step is to figure out what has seized and if its able to be fixed. I have removed the pull starter housing, there is a 3/4" nut on top of a bolt which is holding down the flywheel. It seems the flywheel should be able to come off but wont budge. Any suggestions?

Can anyone point me in the right direction to get this thing running? Resources? I dont need a step by step guide but something so I can start asking the right questions.

Take the spark plugs out and try and turn the flywheel by hand. If no go spray some penetrating oil in the cylinders and let it soak for a day

They make a puller for the flywheel, or you can have a buddy put tension on 2 pry bars and hit the shaft with a brass hammer.

The flywheel is usually torqued down on a tapered shaft. May have to let it soak in some penetrating oil too.

Sounds like ya got a good deal. Free education and you can always sell it for scrap metal

Loggerhead Mike said:

Take the spark plugs out and try and turn the flywheel by hand. If no go spray some penetrating oil in the cylinders and let it soak for a day

They make a puller for the flywheel, or you can have a buddy put tension on 2 pry bars and hit the shaft with a brass hammer.

The flywheel is usually torqued down on a tapered shaft. May have to let it soak in some penetrating oil too.

Sounds like ya got a good deal. Free education and you can always sell it for scrap metal

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Hey thanks for the reply. I sprayed penetrating oil in directly on the cylinders a few days ago. I cant spin the flywheel...i did try to hit it with a soft mallet. Dont have a brass hammer. Ill spray some penetrating oil on it. In the motor, What would most likely bind up and cause this? I tried spinning the prop as well, no luck.

If you don't have a brass put the nut back on the shaft so you don't mess up any threads and give it a few good wacks with a hammer. You need somebody putting pressure on the flywheel while you hit it to help pop it off that shaft

There's no tellin what could be seized, gotta dig in there some more

Looking forward to hear what you find

Was there any metallic looking particles on the spark plugs? Chances are your buddy ran that engine on 50:1 fuel oil mix. That engine is a little early for that and needed to be run on 24:1.
Second thought may be to pull the gearcase drain screw and see if there is metal on the drain screw. May be a seized gearcase not allowing the crank in the powerhead to turn.

It's probably not the best idea to start hitting on the flywheel with a hammer. It can and has happened before where the impact from the hammer affects the magnets in the flywheel. I'm just as guilty as everyone else that has ever done this, so I know it's not going to happen every time. Just be aware that it can happen.

Loggerhead Mike said:

If you don't have a brass put the nut back on the shaft so you don't mess up any threads and give it a few good wacks with a hammer. You need somebody putting pressure on the flywheel while you hit it to help pop it off that shaft

There's no tellin what could be seized, gotta dig in there some more

Looking forward to hear what you find

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Hey Mike thanks for sticking with me...it be nice to have someone I can run through my progress. I have sure learned alot since starting this project. After looking at this I think I have a general idea...

The pull start turns the magneto which generates spark to plugs and initiates combustion.
Combustion turns crankshaft which turns magneto and generates spark for the next stroke.
The fuel line runs to the fuel pump and out to the carburetor, I think the carb regulates the amount of fuel/air?
The fuel and air move through the engine to the pistons, combustion occurs and exhaust runs through and out to lower unit?

This may seem basic to most but It is what I have gathered in the last few hours. I can read read read but until i get dirty I wont absorb anything. Learning all this will make me more confident to service my new 2011 Mercury 4stroke.

Today, I removed the flywheel as LoggerheadMike suggested. At first I was trying to remove magneto to get to motor but after a second look I dont think I need to, to get inside motor. Looks like the bolts running through the motor housing (under the motor) need to be removed so I can raise the motor out from the motor housing. I can then get to the panels that are bolted to the motor.

Should I just start taking panels off, how would I identify what is seized?




Today I also removed the lower unit, this gave me a good idea of how the water pump works. Its in pretty good condition, could just use some cleaning. The oil will need to be replaced in gear case. I also see how the gear shifter connects to the gear case.



Here is something I have a question on...what exactly does this adjustment do? Does it adjust the throttle idle limit?

aeviaanah said:

Here is something I have a question on...what exactly does this adjustment do? Does it adjust the throttle idle limit?

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Most idle control/adjustments are done at the carb but in this case, it does appear that that is exactly what you have there. It appears to have a knurled edge for adjusting with your fingers, so maybe it was a quick and easy way to turn the idle up for trolling.

Maybe late in this suggestion,but an old trick from my buddies in the village I,m from they pour hot transmission oil in seized engines,more often than not it works,,Mike

JMichael said:

aeviaanah said:

Here is something I have a question on...what exactly does this adjustment do? Does it adjust the throttle idle limit?

Click to expand...

Most idle control/adjustments are done at the carb but in this case, it does appear that that is exactly what you have there. It appears to have a knurled edge for adjusting with your fingers, so maybe it was a quick and easy way to turn the idle up for trolling.

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Thanks for helping me clarify that. I found an old service manual for Gale motors, although my motor is a Sea king, Gale manufactured it... this is exactly what the manual said this was.

Mike Redmond said:

Maybe late in this suggestion,but an old trick from my buddies in the village I,m from they pour hot transmission oil in seized engines,more often than not it works,,Mike

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Ok ill give that a try if this penetrating oil doesnt work...should I whack the cylinders with a piece of wood? Another question, if I do get it to break free, how to i get all this oil out before starting it up? Im trying to break it free before getting into the motor itself.

Pappy said:

Was there any metallic looking particles on the spark plugs? Chances are your buddy ran that engine on 50:1 fuel oil mix. That engine is a little early for that and needed to be run on 24:1.
Second thought may be to pull the gearcase drain screw and see if there is metal on the drain screw. May be a seized gearcase not allowing the crank in the powerhead to turn.

Click to expand...

I did check oil in gear case. Looked like dirty motor oil, definitely needs to be replaced. After removing the lower unit i turned prop and it turned the drive shaft, it did have more resistance than i expected but wasn't the cause of the motor not turning. I read post after removing drain plug but I didn't notice any metal on drain plug.

We sure have a lot of Mikes helping out here!

Pappy said:

Was there any metallic looking particles on the spark plugs? Chances are your buddy ran that engine on 50:1 fuel oil mix. That engine is a little early for that and needed to be run on 24:1.
Second thought may be to pull the gearcase drain screw and see if there is metal on the drain screw. May be a seized gearcase not allowing the crank in the powerhead to turn.

Click to expand...

I found out the previous owner ran 50:1 ratio. He told me he cleaned the motor, got it to run came back the next day and it had seized. This tells me the motor overheated and the heat expanded the pistons causing it to seize. Is there still hope?

Although it's probably not something a mechanic might recommend, here's something I've done in the past that freed up a 2 cycle engine that had seized up from overheating. Remove the head and sit the engine where the cylinders are pointed upward. Pour in some transmission fluid and let it set for a day. Then using a large piece of wood just a little smaller than the diameter of the cylinder, place one end on the piston and tap the other end. Don't whack the snot out of it or you could break the piston or rings, but repeated tapping might free it up. Alternate between cylinders. If you manage to get it freed up, turn the engine over until the piston is at the bottom. Inspect the cylinder walls. If they aren't scored too bad, it might still make enough compression to run. Of course this is not going to fix any damage that has already been done but it might get it running well enough to use for however long it last.

JMichael said:

Although it's probably not something a mechanic might recommend, here's something I've done in the past that freed up a 2 cycle engine that had seized up from overheating. Remove the head and sit the engine where the cylinders are pointed upward. Pour in some transmission fluid and let it set for a day. Then using a large piece of wood just a little smaller than the diameter of the cylinder, place one end on the piston and tap the other end. Don't whack the snot out of it or you could break the piston or rings, but repeated tapping might free it up. Alternate between cylinders. If you manage to get it freed up, turn the engine over until the piston is at the bottom. Inspect the cylinder walls. If they aren't scored too bad, it might still make enough compression to run. Of course this is not going to fix any damage that has already been done but it might get it running well enough to use for however long it last.

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I tried tapping cylinder with a piece of wood but cant get a square hit with bottom cowling still attached. I think i need to remove power head from everything else first. A user at another forum mentioned removing carb and intake to hit the crankshaft. Not sure what I will end up doing. Hopefully someone else will chine in with their input. I plan on getting something done this weekend.

Go ahead and pull the pwr head it may be your only option

Sort of read through the previous posts.

Have the plugs been pulled? I see your lower unit is removed, so with the plugs pulled, it should be easy enough to turn the flywheel by hand. If not, I would assume there is a major internal problem in the power head.

I've overheated outboard before to the point they stopped running but after a quick cool down, they always fired up and ran again even with no water pumping!

Nothing like getting your hands dirty! Good luck.

Update, so i couldnt free up the motor from the pistons or from the small view of crankshaft through the intake manifold. I ended up splitting motor in half. I have got the pistons out everything is in pretty good condition except for piston rings and a bearing. Hopefully I can find replacement parts for this model. Any suggestions? Ill go ahead and start a thread for that.

...a few parts need to be replaced before I reassemble.

-piston rings (i was told to always replace these) piston rings where stuck to piston
-one crankshaft bearing

i was also told i need to address the crankshaft a bit when i buy the new bearings. polish it out. i also need to rehone the lower cylinder.

I just sprayed everything down with degreaser and am getting ready to do the first pass of cleaning the parts.

nomowork said:

Sort of read through the previous posts.

Have the plugs been pulled? I see your lower unit is removed, so with the plugs pulled, it should be easy enough to turn the flywheel by hand. If not, I would assume there is a major internal problem in the power head.

I've overheated outboard before to the point they stopped running but after a quick cool down, they always fired up and ran again even with no water pumping!

Nothing like getting your hands dirty! Good luck.

Click to expand...

Hey thanks for stopping by...im gettin ready for my first rebuild. Im sure learning alot about this stuff. Plugs have been pulled, power head is disassembled and is getting ready for a good cleaning. Needing to find replacement parts tho.

Any time you replace rings, you need to hone cylinders at minimum. So If you put new rings in both, hone both.

JMichael said:

Any time you replace rings, you need to hone cylinders at minimum. So If you put new rings in both, hone both.

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Man I was told I needed to replace rings. How can one tell?

Itd would have been nice to reuse them but they cracked as I was taking them off.

Ill be sure to rehone both cylinders if I can find rings.

Although rusted a bit the cylinder bores appear to be pretty normal looking. The engine had not been run for several years and has the original ignition coils in it. That is normally a good sign of an engine that is worth putting back into service. Your buddy is not on track with his diagnosis. Having run the engine on 50:1 instead of 24:1 will do a great job of seizing that engine. Your engine has plain bearings in it instead of roller bearings and needs the extra lubrication to survive. However, your cylinder walls look good. Would suggest at this point to remove the powerhead, remove the carb, intake manifold and reeds and have a look in the crank area. You may find your issue. Overheat sticking normally occurs on the exhaust side of a two-stroke piston and the damage is easily visible on the side of the cylinder wall. I cannot see the other side of the cylinder walls from your picture but the side that I can see shows me no reason for the seizure. Keep us in the loop. By the way, all gaskets are still available for your engine as well as all ignition parts, carb rebuild kits and gearcase seals and water pump parts. Everything you need to get that classic back on the water.