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by Max Wawrzyniak - St Louis, Missouri - USA

Bringing a 1956 Johnson 15 hp Back to Life

Part 1

Part 2 - Part 3 - Part 4 - Part 5 - Part 6 - Part 7

Well, it's Spring time and the time of year that all young men turn to thoughts of Messabouts and Antique Outboard Motor Meets. And I decided that this would be the year that I pulled the 1948 aluminum Feathercraft boat down out of the rafters of the garage (where it has been for about 7 years) and actually got it into the water.

click to enlargeThe 1948 aluminum Feathercraft boat has been hanging from those rafters for several years. At only about 11 feet in length and less than 4 feet wide, 15 hp ought to be plenty for the little boat.

(click images for larger views)

Since it would need an engine, I went to the storage shed to see what I had that was suitable, and eventually selected a 1956 Johnson 15 hp that I have owned for an equally long time, but have never done anything with. And so begins the 3rd "Start to Finish" saga, where I take an old outboard from "as-found" condition to "running " (I hope) condition.

Since I had used a 5 1/2 hp outboard in the first "Start to Finish" series of columns, and a 25 hp in the second "Start to Finish" series of columns, I decided that the 15 would be a good choice, if for no other reason than it splits the difference in horsepower between the other (2) engines. Sort of like Goldilocks and the three Bears. "Just right."

1956 was a good year for outboard motors. More outboards were sold in 1956 than in any year before or since. Sterndrive boats did not exist in 1956, but even if sterndrive sales figures are included with outboard motor sales, today's unit sales still don't come close to 1956.

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The 15 hp Evinrude made its first appearance in 1953 but a Johnson version was not available until 1956. The 1953 & 1954 Evinrude 15's are about the lightest 15's around, even when compared to modern 15's, but without sound proofing or vibration-absorbing mounts they are not the smoothest or quietest outboards around. The 1955 Evinrude 15 was a more civilized engine which featured improved sound and vibration control and a much-improved tilt adjustment mechanism. The only fault I can find with the '55 15 is a somewaht weak recoil starter housing. Most recoil starter damage, however, is due to operator error. The correct way to use any recoil starter is to slowly pull the starter handle until the starter is felt to engage the flywheel, then give a firm, brisk pull. What many people do is grab the handle and give it a hard jerk which causes the recoil starter to slam into engagement with the flywheel. Eventually, something breaks.

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The 1956 Johnson 15 hp, looking a bit faded and worn, has been sitting on the rack in my storage shed for years. Time to dust off the cob webs and mud dauber nests and put the old engine to work.

The 1956 15 was the final refinement of the Evinrude (and now Johnson) 15, featuring an improved recoil starter design and a flywheel modified to prevent gasoline vapors from entering the magneto and possibly causing a minor explosion (a somewhat remote possibility, in my opinion). In 1957, the cylinder bore of the 15 was
increased and the horsepower was upped to 18, and 18's continued to be produced up until the early '70s.

The 15's (and the subsequent 18's) are just about the largest outboards that one can (somewhat) comfortably carry and mount on a boat. They provide plenty of power for the size boats that most of you guys build (a 1957 18 is the engine I use most often on my Jim Michalak-designed AF4). And finally there were many of these engines sold during the '50s and '60s and they are not too difficult to find.

The Gale 15's from the early '60s are virtually identical to the 1956 Johnson 15 except for cosmetic details. For that matter, the Johnson and Evinrude 18's that supplanted the 15's are also virtually identical except for cosmetic details and cylinder bore diameter.

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Although this series of columns concerns the 1956 15, all of the information is applicable to the later 18 hp models which were almost mechanically identical to the '56 15. The Gale 15's (see Gale Warnings column) can also be included, as can the 10 hp models of the '50s and early '60s. All of these engines utilize the same ignition components, the same carburetor rebuild kit, the same water pump impeller and the same recoil starter spring. As a collector of old outboards, I tend to prefer the styling of the older versions, but the same basic engine resides under the more modern cowls and paint schemes of the models of the '60s.

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Pretty scruffy looking, but the plan is to re-paint once the engine is in running condition.

Once I had the 15 out of the storage shed and brushed-off the obvious mud dauber nests, I gave the starter rope a pull to ensure that the engine was not "frozen" or "locked-up" (i.e. that the pistons were not siezed in the cylinders) and also to get an idea of the compression of the engine. An engine that has seen many hours of use, or that has been run with too little oil mixed in with the gasoline, or that has piston rings stuck in their grooves from carbon build-up is not going to have much compression. The proper way to check compression is with a compression gauge. What I do is firmly pull the starter rope and listen and feel for a solid-sounding "thunk-thunk" from the two cylinders. No very scientific nor an always reliable method of checking compression, but then I live dangerously. Anyway, the '56 has a decent-feeling thunk-thunk.

Obviously this engine has spent a lot of time sitting on a boat in the water, and the former owner(s) neglected to tilt the motor out of the water when it was not being used. The original paint is completely gone and the aluminum castings show a bit of pitting.

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A visual check of the outboard revealed no missing parts; all of the knobs and controls where in place. There appeared to be no obvious damage such as broken castings. The paint and decals were in a horrible state. Evidently this outboard had been left outdoors for extended periods of time, and the brownish-red "Holiday Bronze" paint as completely faded away in many areas, leaving few traces on the white undercoating. The decals were "toast." I was not overly concerned with the paint and decals, however, as I intended to repaint the motor anyway, and I would much prefer to repaint a lousy-looking engine than one that was pretty-good looking.

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The mud daubers love old outboards. Although they usually prefer to build their nests under the hood somwhere, this old engine even has a nest on the control panel.

One aspect of the outboard's conditiion that stood-out was the lower unit. It appeared that the motor had been left on a boat in the water with the motor tilted down much of the time; the lower unit showed signs of long-term immersion. The possible results of this abuse are corroded fasteners, corroded shafts and gears caused by the long-term presence of water in the lower unit oil, and even corroded castings. While not a good omen, I decided that the outboard was still worth trying to bring back to life.

Next month will cover removal of the lower unit for replacement of the waterpump impeller.

... on to Part 2...

click here for a list of Columns by Max Wawrzyniak