# 1951-52 Johnson Seahorse 10 hp QD-13



## zackn (May 7, 2010)

I've been watching craigslist like a hawk to try to find a decent motor for my 1st boat (12' semi-v fixer-upper, thread here: https://www.tinboats.net/forum/viewtopic.php?f=3&t=13413&start=10). Not much available here in Omaha area... at least in my price range for an older Johnson or Evinrude. The few I've tried to buy, I've missed out on by someone swooping in and offering more than the listing price, or the seller being a flake.

So I happened to see this beast at an auction yesterday, and grabbed it for $35.

It's a Johnson QD-13 10 hp, which I think makes it 1951-52. Running condition unknown. I figured for $35 it was worth checking out. Of course as this is my first outboard that I bought on a whim, I didn't know what I was getting into. Now that I'm researching more, I realize that it needs the pressurized gas tank and dual lines (which are missing).

So I figure I'll check this out and see how bad it looks. I've heard the pre-1954 Johnsons are harder to work on, and this is my first motor. I don't have a service manual for it, and I'm a little nervous to spend as much as I spent on the motor on a manual... which I might not even use if it looks like the thing needs $200 in parts. I might try out what they're talking about in this thread on iboats--https://forums.iboats.com/showthread.php?t=277487. That could be a good start.

--Zack


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## Loggerhead Mike (May 7, 2010)

great lookin motor for the year i would of picked it up in a heartbeat. if it cant run atleast it will look good hangin on a wall in the garage

first thing i would do is let some oil soak in the cylinders, clean and re-set points along with ohm'ing everything out while its apart

got a pic of the motor itself?? very curious to see what they look like


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## lckstckn2smknbrls (May 7, 2010)

Converting to a single fuel line and fuel pump is said to be an easy mod. Just make sure the gas to oil ratio correct.


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## zackn (May 7, 2010)

Thanks, this makes me feel a little better. I did read a couple articles about the fuel pump mod. Not sure if it's something I could tackle, but I'd like to try to learn.

I'll get the cowling off tonight and upload some more pics of the inside....

Anyone know if the PDF manuals that Jim distributes through Dropbox include any manuals for this motor? (parts, service, or user) I'm still new to the board and don't have enough posts to qualify for the Dropbox thing yet, but if they are there, I might hold off on buying manuals online.

--Zack


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## zackn (May 8, 2010)

It must be a good omen (right?) I went to an estate sale tonight and found the pressurized tank I think I was missing for the Seahorse--for $20. Haven't tried it out yet, except to pump it up and it seemed to hold pressure fine. It sure is an obsolete design, but the thing is really cool! Well, it's probably not any kind of omen as to whether the motor will be shot or not, but it was a weird coincidence anyway.


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## zackn (May 10, 2010)

I finally got the cover off and had a look underneath. I hooked up a compression tester, and got readings of 60# for each cylinder. That seems kind of low, but at least the numbers were the same. I had a lot of resistance from the pull cord, and I had to pull pretty hard to get the flywheel to turn. I'm just glad it's not frozen up completely.

I bought a Johnson shop manual on CD, and that should be here soon. I'll definitely need that since I don't know what I'm doing. Hopefully I won't be in over my head right away.

At the estate sale I went to last weekend, in addition to the pressurized fuel tank,I bought a couple spare early 50's Johnson propellers for $6 a piece... so that was a good find.


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## Loggerhead Mike (May 10, 2010)

it may be just gum or a funny shot from the picture but it looks like somebody used rtv or a liquid sealer for the head gasket? if so replace that with an oem gasket

you've got a sweet find man prop it up and let some oil soak on the rings before trying to turn it over. no tellin how long its been dry

it should run fine on 60lbs of compression. 

i love the simplicity of those motors. good one to learn with ive got faith she'll see the water again


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## zackn (May 10, 2010)

Thanks Mike, glad to hear that about the compression. And I'll check out that gasket for sure. As soon as I get that service manual, I'll oil the cylinders and work on the points as you suggested. 

I was checking out this article:
https://www.sschapterpsa.com/ramblings/johnson_QD.htm

And he mentions this:


> Go to your local NAPA automotive store. They have a marine products catalog that shows #18-5181 replacement coil that is supposed to fit 1949-1963 10hp Johnson. Looking farther, it is a pretty standard coil that fits many other motors from 1.5hp up to 30hp. They also show points & condensers. The tune-up kit (the whole set of 2 points & 2 condensers) is #18-5006.



Maybe I should check that out.


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## Loggerhead Mike (May 10, 2010)

good websight thanks. I got most of my parts threw carquest, almost all of the auto chains carry a sierra marine catalog. you'll be suprised how many guys you get on the phone that dont even know they can get marine parts :LOL2:


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## arkansasnative (May 11, 2010)

good luck with it man! ill be keeping an eye on this thread... im in the process of bidding on a 50-51 model johnson qd-11! right now im at 60 bucks but its fully restored so i imagine its gonna shoot out of my price range soon lol


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## Pappy (May 15, 2010)

Your engine is a good one. In all probability you will need new coils, water pump impeller and probably a carb kit if you can find one. The carb can be flushed with fuel pumped from the tank after removing the high speed needle (the lower one). A really good tune up would include new coils, points, condensors, carb kit, water pump kit, new gear lube, and new seals in the lower unit. The tank you purchased may work fine but just in case, new replacement parts are still available in the form of gaskets, seals, and double line fuel hose. Your fuel/oil ratio for the engine is a minimum of 24:1. Never run less oil than this. The engine has bushings where the newer engines have roller bearings and can easily run with less oil. If you are not planning on replacing lower unit seals by all means check the oil frequently for water. Almost all parts mentioned above are still available from a reliable Johnson/Evinrude outlet.


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## zackn (May 19, 2010)

Pappy said:


> Your engine is a good one. In all probability you will need new coils, water pump impeller and probably a carb kit if you can find one. The carb can be flushed with fuel pumped from the tank after removing the high speed needle (the lower one). A really good tune up would include new coils, points, condensors, carb kit, water pump kit, new gear lube, and new seals in the lower unit. The tank you purchased may work fine but just in case, new replacement parts are still available in the form of gaskets, seals, and double line fuel hose. Your fuel/oil ratio for the engine is a minimum of 24:1. Never run less oil than this. The engine has bushings where the newer engines have roller bearings and can easily run with less oil. If you are not planning on replacing lower unit seals by all means check the oil frequently for water. Almost all parts mentioned above are still available from a reliable Johnson/Evinrude outlet.



Thanks Pappy, I appreciate the info. I was under the impression that the oldest Johnson 10hp you could get a carb kit for was a 1954? But I may not be looking in the right places.

I'm planning on getting coils, points and condensers from Napa/Sierra. I think I have the right part numbers... #18-5181 for the coil, and #18-5006 for 2 points and 2 condensers. Planning on a new impeller and seals, but I still need to track those down.

Yep, planning on 24:1 with TCW-3 oil. Also going to get new plugs. I read HERE that Champion J6J were recommended, but for a well-used motor a hotter plug such as a J8J might be better. A thread on iboats recommended J6C. Not sure which of these is correct for me.

I just got my service manual on CD rom, but I still need a parts catalog. I think I'll go ahead and buy that and a user manual from Ken Cook.


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## BaitCaster (May 20, 2010)

This is a good thread. I've been looking at a number of late 50's Johnson and Evinrude motors. From what i have learned they are well built and will last a very long time.


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## Pappy (May 23, 2010)

Would not go with a J8 plug on that engine. The engine will surprise you with how well it will run and perform on the recommended plug. The 50's engines are built like tanks and will, with common sense and a little maintainence, outlast us and hopefully serve the next generation as well. I have two of these engines, one built and running and the other is in a box with all new rings, gaskets, carb kit, ignition components, etc, just waiting on me to put it back into service.


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