Small 1950's Johnsons

Trackbolt

Petty Officer 3rd Class
Joined
Jul 12, 2007
Messages
98
I was on the west coast of Florida in the Ft. Myers area and managed to pick up two Johnson Motors from the 1950's. I was out looking at flea markets for a couple of six gallon pressure tanks for my 58 Evinrude project when I came across a 1954 QD-15 10 hp Johnson and a 1955 CD-12 5 1/2 hp unit. The 10 hp was by far in the best of shape as it had been shed or garage kept. The 5 1/2 Johnson on the other hand was a trolling motor on the back of a delelict Wellcraft on a trailer in sombody's yard. It looked as though it had rode to the bottom on the Wellcraft and was stuck to boot. Both motors came with six gallon pressure tanks with hose and fittings. The owners of both units let me go over the engines. The 10 hp had spark and a even 100 psi in both cylinders. The 5 1/2 engine had clean lower unit oil and the spark plugs looked normal with no signs of rust on the plugs. I offered the guy $20.00 for the 5 1/2 and the other guy $50:00 for the 10 hp. They agreed and I happily took them and the tanks home to MD. I changed the lower unit oil in the 10. The old oil had no signs of water intrusion. I put it in a 55 gallon drum shot a few shots of seafoam in the plug holes hooked up the gas and it fired and ran on the second pull. It was pumping water well but I will replace the impeller before it sees the river, I removed the spark plugs from the 5 1/2 and poured in some seafoam and marvel mystry oil and let it work its magic. The next day I was able to turn the flywheel with a hand effort. After some spins by hand I checked the compression and to my suprise both cylinders were at 95 psi. The lower unit oil too was free of water and looked normal. I am not sure if the 10 hp was a salt water motor as there is virtually no corrosion visible. The 5 1/2 is another story. As I said earlier it looked like it was on the bottom of the Gulf of Mexico on the outside. I am going to pull the head to look at the cylinders and water jacket. That should tell the story. I have yet to finish my 58 Evinrude/Alumacraft project but the two six gallon tanks I secured with these to Johnsons are helping me get to where I want to be. From everything I have read the two small Johnsons I now have were nice motors in their day. I will post a picture or two of both motors very soon.

Thanks

Tony
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: Small 1950's Johnsons

I wouldn't even mess with the 5.5. I would just tune it up and run it. 95 psi per hole is excellent. I own two of those and had several others in the past and they are great motors and for $20, you stole it :D:D
 
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jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: Small 1950's Johnsons

I wouldn't even mess with the 5.5. I would just tune it up and run it. 95 psi per hole is excellent. I own two of those and had several others in the past and they are great motors and for $20, you stole it :D:D

Major dittos!! I can almost guarantee you will have broken head bolts on that thingj if you try to remove them. I think 95 and 100 on those motors is a little higher than they actually are, just due to a high reading guage. But either way, that's SUPER compression on both and no reason to pull the head. If the water jackets have a lot of corrosion, what would you do about it anyway??? Replace the impellers, clean the carbs, replace fuel lines and check the coils under the flywheel for cracks and clean/regap the points and enjoy. Watch out, 50's OMC's are quite addictive and you could have a yard full before you know it. DOn't ask how I know. I've actually only bought one in the past few years so I've "beaten" the addiction as far as I can tell. :)
 
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