Beyond the Sea…horse!: Outboard motor restoration step by step…Day one!

All to often members of our Antique Outboard Collectors Club seem apprehensive, or at least mystified by all the things that are involved in full outboard restoration.  To fully restore an outboard motor properly you have to be librarian, historian, technology buff, technician, sleuth, wheeler-dealer, mechanic, blacksmith, artiste, body shop tech, electrician, cable rigger, forensics expert (novice), and a host of many more talents come in very handy.

Most of our members are amazing at some or all of these aspects of the hobby.  We have many who are simply amazing in their ability to resurrect the “remains” of an old detachable rowboat motor into an operational museum piece.  Some restore motors for display, and some simply return them to operating condition without all the pretty-business being a concern.  Some of our members also are very particular to purchase for their collection only old motors in amazing original condition.  You’d be amazed how many old survivors are out there hiding in garages and basements.

Either way, AOMC is an amazing array of folks to get hooked up with if you are getting into the hobby or just wish to get your old outboard running again.

I am not by nature a “motor-head”!  However seeing an old motor come back to “like new” condition is an amazing experience.  It is my personal preference not to care much about the cosmetic condition of an old outboard when buying one.  My concern is whether it is complete with all parts, and if now are parts able to be procured?

So with this blog post I hope to be able to take you through the basics of how the restoration process have developed for me and the sequence of events I use.  With that said, there are too many outboard motors to show every little nuance of dis-assembly and repair/restoration in it’s entirety.  Instead we will look at basic steps with accents on parts of the project I get the most questions about.  We will address basics of dis-assembly, parts storage for ease of location, cleaning, paint removal, re-assembly, prepping for primer and paint, priming and painting, and decal-ing using vinyl and water-slide decals and clear coating for their protection.  We also take a look at examination of the motor for repair and creating a checklist to keep us on track throughout the project.  (Authors note: I would add this is the system that works for me.  Everyone has their own system.  I’m no expert…so take what you can from this and use it at your own risk!!!)

The project featured in this series will be an OMC outboard, but one that is slightly irregular from the “modern OMC” of the 50’s when Johnson Evinrude and the “bastard step-child of OMC”…the Gale Div. motors began to be standardized, sharing most parts and designs.  This “standardization” began in the mid 1950’s, and parts are still readily available for most of those motors.  Fortunately, some of our AOMC members have started “Cottage industries” supplying parts for some of the outboard of earlier vintage with hard to find parts.

Lets take a quick look at some vintage OMC-style motors.

This 1937 Johnson PO is a motor that was fairly simple and reliable. The basic design was spread out both pre and post-war under different designation and variations.

The PO was around many years before and following WWII.  This motor chimed in with a “whopping” 22HP.  The design had deviation, but largely all that changed was the color.

This is a late 40's Johnson TD-20. The basic power-head design again was used pre-war and post-war. The designs were likely held over owing to manufacturing being for war production, therefore not allowing many new advancements in outboard motor technology...a luxury.

This is a 1954 Johnson RDE-16. This motor design first made its appearance in 1951 as an RD-10, and the basic design of the power-head would remain a staple of the OMC design for many years. With increases in horsepower using advances in piston size, crankshaft and carburetion, these motors reached 40hp by 1960. This particular motor was the first year the "Big Twin" was available with electric starting!!

Our "Chief of the Boat" Remy Marco Jones enjoying the quiet advances of the OMC "Super Silent" exhaust leg on a 1959 Evinrude 35hp Lark!

While we now have a basis on the OMC design, our motor is a “transitional motor” in that it has a non-standard carburetor and lower unit, but does have the “universal magneto ignition” that survived for decades on many, many OMC models!  Our project is a 1951 Johnson QD-12 rated at 10hp at 4000 rpm.  She will, when finished, be the primary power for our 1948 galvanized steel Star Tank & Boat Company rowboat.  In fact this motor is ideal for our little vessel to push us leisurely along for a relaxing trip on protect waterways.

Now without further adieu…here is our specimen!

Looking rather worn, this outboard is in fact in pretty good shape at first look. We'll see how she looks after further triage.

The hood on the early "QD" series was very cool and streamlined! The one on our motor was cracked on the port side, so a replacement was found at a swap meet for 10 bucks. (Pictured here.) However, it was also a pain in the rear since it took almost one dozen screws to hold it on the motor. The later easy-flip open hoods were much easier to deal with...especially at sea! Believe me I know!!

Upon examination of this photo you can see the throttle is more crude than the well known twist-grip throttle that came later. This motor has a synchronized spark advance and carburetor controlled by the sliding lever under the pull start.

The first sign of potential trouble shown by way of damage that has broken through the casting of the exhaust housing on the leg of the motor. This would take a fairly serious impact to create such damage.

The next sign of potential problems is the cowl (hood) bracket on the port side is also cracked and welded back into place. This would indicate to me that this motor has had a collision somewhere in its long life. This would fall in-line with the other damage found above. Outboard battle scars!

Something seen less often is inflicted by dealers who sold these motors, or owner who had to have the most latest-greatest motor. This fuel connector shows the original Sea-mist Green paint. BUT...look at the next photo!

The throttle lever has Sea-mist Green...but the body and the flywheel have shades of the later Sea-horse Green. Sometimes dealers or owners would "update" the color of "last years model" to move it out of inventory when the color change with a model year. The dilemma now is paint as manufactured or as found? For me it is a no-brainer. But I'm not saying which way we'll go with the project yet!

Using a flywheel puller from the local auto parts store, and three grade 8 hardened bolts, the flywheel must be removed to get to the magneto ignition. This can require considerable force to break the flywheel free from the crankshaft. An occasional "whack" with a rubber mallet on the side of the flywheel while under pressure can assist in this operation. NEVER...NEVER smack the flywheel on the top or bottom sides...as this could damage the crank or bearings!

The magneto has been update somewhere along the way. New coils would point to this. The original OMC coils of this era ALWAYS crack and fail and require replacement. These coils are readily available. at any OMC Dealer.

With the cylinder head removed, the pistons seem to be in pretty good shape. There is less carbon build-up than I thought a motor of this vintage would have. This again would bear out the initial thought that this motor has had little run time. The cylinders show little wear and no serious scoring or scuffing.

This view of the power-head shows the handy-dandy shift handle sticking out in front of the motor. This is very handy and a great feature on these older "QD" motors. However, to remove the power-head, the shift linkage must be removed.

After removing the power-head and other parts, the steering shaft is ready for disassembly for ease of cleaning and eventual cosmetic work.

This prop shaft has so much twine wrapped around the shaft, it has gotten between the rubber seal and the brass casing and actually caused the brass to bend out.

Fortunately the prop shaft was not ruined by being groove from the fishing line. The seal will be replaced anyway, but it is amazing the force that has been put on the seal!

Fishing line is a death knell for lower unit seals.

This motor has probably been used, per manufactures directions, with 30wt motor oil mixed into the gasoline. The carbon build up in the exhaust side is evident.

So after Day One, we have a pretty good grasp of what service will be performed on out motor. Now it is time to clean up parts and strip all the old paint off, We'll save that for Day Two!

So after 3 1/2 hours of work the motor has been disassembled and placed in storage containers for safe-keeping until Day Two when cleaning of each part, nut, bolt, screw, and all paint will be removed after degreasing.

Hope you’ll check back in with part 2 here: Beyond the Sea…horse!: Outboard motor restoration step by step…Day Two.


11 Responses to “Beyond the Sea…horse!: Outboard motor restoration step by step…Day one!”

  1. 1 David
    December 12, 2011 at 7:32 pm

    G-man, you are awesome to contribute to the knowledge base of our AOMCI members. Sincerely appreciate your kindness and efforts!!!!


    • 2 conductorjonz
      December 12, 2011 at 7:36 pm

      Hi David!

      Thanks for the kind words. I love our club. We have so many great members, Frank Robb and Garry Spencer being two of my heros. Our M.O.B. Chapter has some very talented folks as well. I have also visited the Florida group for the last two years in February. Steve Woods and many other who are absent from the web are simply amazing members!

      Good luck!


  2. 3 al
    December 12, 2011 at 7:50 pm

    Very cool please notify us when more is posted

  3. 4 Bob Whalen
    January 25, 2012 at 2:12 pm

    Is there a paint in a name brand aerosol that is a close match for the johnson sea horse green and cream . I’em restoring a JW-11 1955 3 HP twin.

    • 5 conductorjonz
      January 25, 2012 at 2:44 pm

      Hi Bob!

      None I know of. NY Marine sells ggod quality paint that goes along way. Two cans of seahorse green would do a JW with a bit to spare.

      Good luck!


  4. 6 Bob Whalen
    January 25, 2012 at 3:02 pm

    Thank you very much for the info. Bob

  5. 7 Ryan
    April 8, 2013 at 2:34 am

    Hi, I know this is an old post, but I picked up a 1954 5.5 Johnson, and it started. What a relief, but when taken out, it went so slow that I could row faster! So I cleaned the carb, still low rpms, replaced spark plugs, did a usual tune-up, but still nothing spectacular. So I took the head off and looked at the pistons, they had some carbon build-up but weren’t that bad, then when I rubbed my finger on a piston, it wiggled back and forth. I decided that I was going to need to put on new rings on the pistons, so I took the manual pull rope off, along with the flywheel, but I don’t know how to take of the mag needle, can you show me what screws to take off? This would help out a lot!

    • 8 conductorjonz
      April 10, 2013 at 5:52 pm

      That sounds like you’re running on ONE CYLINDER! Well the motor is anyway!

      Here the deal…those old OMC Motors will run fine on one cylinder. You should probably remove the recoil starter and peek in at each coil under the flywheel though the inspection port in the flywheel and see if either coil is cracked. The original 50’s vintage coils all crack, then even though they may show signs of spark in testing, once they are under a load, IE:Pushing a boat…they will fail.

      Short of this check the ignition points are gapped at .020″.

      To remove the magneto, back the flywheel screw off, place a pry bar under the rim of the flywheel, bracing it solidly and give the top of the crank a sharp rap…maybe two or three…to break the flywheel loose. Having a friend help with this is a good ideal. Then loosen two captive screws, one each on the CORNER of each coil, and ONE EACH between the breaker points and the coil heel on the opposite side. Then the mag plate should come free for servicing.

      However, since you removed the head gasket, make sure you use a new one…NOT THE OLD ONE! Make sure to torque the head bolts to the proper specs too.

      Also be aware the 5.5’s sometimes had a tendency to snap the lower cylinder connecting rod, but this renders the motor pretty much locked up and it will not run, but if you ever open the block, make sure you inspect the rods for fractures.

      Good Luck!


  6. 9 David
    November 10, 2018 at 1:32 pm

    I am trying to find someone to restore my grandfather’s outboard motor (Martin 60). Do you know anyone who restores outboards for hire?

    • 10 conductorjonz
      August 16, 2019 at 8:39 am

      Google Martin Motors and the parts and manuals are still around. A member of the AOMCI owns the brand now. Try AOMCI.org

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