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Td 20 Service Manual Td 20 Seahorse Manual Vintage Johnson TD 20 outboard owners manual excellent This is an excellent Johnson TD 20 owners manualT is the slightest notation upper right corner classified search results for 5hp johnson outboard td Johnson 5 HP TS TD15 Outboard Motor Parts Catalog Manual Johnson Seahorse 5hp TD-20 Outboard. You may ignore any letters before the horsepower designation, and those after any of the following model numbers that match yours (e.g. Your 20 HP model # J 20R69 M would match 20R69 in the chart, ignoring the 'J' and 'M'). The first is a wonderful old 1949 Johnson TD-20 that was sent my way by the local marina who was asked to take it on trade in. They of course laughed at the poor guyand instead told him to call me. I went to see the motor and it was not only not running, but was seized up. The tank on the top of the motor was badly dented, and the lower.

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1922 to 2007 Johnson Outboards at 85!
In 2007 the Yankee Chapter of the Antique Outboard Motor Club celebrated the 85th anniversary of Johnson outboards. Johnson was the featured marque at the Yankee Chapter Formal Meet in September 2007. Herewith below is a brief overview of the beginnings of the Johnson brand and some helpful information to get those old Johnsons running again!

Johnson Outboards 1922 - The Beginning Years

Johnson outboard motors made their public debut at the New York Boat Show in January 1922. It is unlikely that the Johnson brothers; Lou, Harry, Clarence and their brother-in-law Warren Conover, had any idea of the impact their little outboard would have on the world of boating.

The Johnson brothers were cut from the same cloth as many of the great American engineers of the early part of the 20th century. From relatively humble beginnings in Terre Haute Indiana, the Johnson’s became some of the premiere engineers of their day. The manufacturing of their small two cylinder outboard would not look very grand on their resumes when compared to building the first American monoplane, aircraft engines and record setting inboard speedboat engines, yet outboards would be their most lasting achievement.

The small 2hp outboard that went on sale in 1922 had its roots in failure. After their aircraft and engine factory was destroyed in a storm, the brothers concentrated their efforts on a small two cylinder air-cooled motor that they adapted to be used as a helper engine on a bicycle. These Johnson Motor Wheels sold well for several years, but the economies of scale with which Henry Ford and others could produce automobiles rapidly eroded the market - after all, who would buy a motorized bicycle for the same cost as an automobile?

Typical of the determination Americans had at the time, Lou Johnson was able to adapt some of the Motor Wheel’s engine to a new purpose; an outboard motor. The water cooled 2 cylinder outboard would weigh in at only 35lbs, this was about ½ that of the typical cranky rowboat motors of the day. Six pre-production motors are believed to have been produced, full-fledged production began with serial number 507. There can be no doubt that the Johnson’s hit a home run when sales for their little $140 outboard topped 3324 units their first year.

Why was the Johnson's little outboard such a tremendous success? In addition to being lighter in weight, the Johnson Waterbug or Light Twin (Both names were used in the advertising) incorporated many features that we take for granted today but were revolutionary in 1922. A key component was the reliable flywheel magneto from the Quick Action Magneto Co of South Bend IN - later to become part of the Johnson company. Many outboards in 1922 used battery ignition and some still had large gear driven magnetos like the ones used on cars & tractors. The Johnsons Quick Action Magneto was small, compact and among the most reliable ever constructed. This magneto proved so good that the majority are still working 85 years later!

Another feature was the use of a rope to start the motor. Here again, Johnson set the trend over the competition who used “knucklebuster” knobs, leather straps or required the operator to wrestle the flywheel to start their outboards. (These were the days long before OSHA!) The rope start was simple, relatively safe (as long as you don’t whip someone with the cord!) and effective.

There were a number of other novel features incorporated in the Johnson outboard; the easy to use and reliable carburetor with three settings; Choke, Fast & Slow. A simple piston waterpump to cool the motor was employed for many years. And to keep the motor on the boat but still make it detachable in a jiffy, secure screw-type transom clamps were used. (Some outboards required you to bolt them on the transom!) The ability to tilt the motor up when beaching or in shallow water was also a rare on other outboards in 1922. While these features may be commonplace today, the Johnson brothers were the first to combine all of them.

One of the most welcome and useful new features on the Waterbugs was the ability to turn (or swivel) the motor through a full 360 degrees. This gave the operator much greater maneuverability and a positive acting reverse for bringing the boat into the dock. While this feature had been used for some time by the European brand Penta, (the Johnson’s licensed it from them), Johnson was the first US company to popularize it. This feature met with immediate public acceptance and is still incorporated on many small outboards today.

The success of the Johnson outboard and its variants; salt water (brass & bronze), canoe mount and even the very rare Model F inboard, was immediate and far reaching. Almost overnight the Johnson’s were producing more outboard motors than anyone else in the world and they worked hard to keep the lead.

The Model A received an update in 1925 becoming the A-25 and also received a single cylinder brother the J-25 the same year. In 1926 a larger motor called the Model P and rated at 6 horsepower, was introduced. Each subsequent year more models and higher horsepower models were produced, outboarding having caught the publics fancy in a big way! Competition from rivals like Ole Evinrude’s second company Elto, Lockwood and the original Evinrude firm, created a swarm of advancements in technology & horsepower. Johnson lead the way with many new features in the late 1920’s; rotary valving, higher horsepower and, possibly their crowning achievement, the smooth alternate firing A and K models of 1930. (1929 was the first time the famous Sea Horse logo appeared!)

The success of the Johnson brand right from the start set the pace for decades to come. Even after becoming part of Outboard Marine & Manufacturing Corporation (later known as OMC), Johnson was still the one with the firsts: first with remote fuel tanks, first with full gearshift, first manufacturer to make 1 million outboards and many others!

Model Identification

Johnson outboards from the 1920's and 30's will have their model and serial number on the top of the flywheel stamped into the rope sheave. (See photo below)

The newer hooded models will have the number stamped into the front of the gas tank or on the port (left) bottom side of the block about ½ way between the front & back of the motor. (You may need to remove the cowl to see the number)

Click on the .pdf file below to see a listing of all the Johnson models from 1922 to 1942. (You will need the Adobe PDF viewer to see the link)

The age of a specific motor can be obtained by simply reading the serial number and comparing it to the chart below. It has been observed that some serial numbers will fall into a different year from the model they depict, this is because a motor was produced at the end of the calendar year for sale in the new year. (An example is the webmasters HD-39 that has a 1938 serial number) Also different will be Canadian Johnson motors - the below is only for South Bend or Waukegan produced motors:

Caring For Your 1922-42 Johnson Outboard Today

Due to the number of models produced from 1922 to 1942 it is next to impossible to completely cover all the service and maintenance differences unique to each. Here is a very brief overview to consider should you be looking to put one of these motors back in service.

Magnetos and Spark Plugs

The early Johnsons all used Quick Action magnetos and these have proven to be very durable and reliable. In most cases the coils themselves are fine however it is likely the condenser will need to be replaced - any 2 microfarad equivalent will work. It is also recommended that the spark plug wire be replaced since most will have deteriorated to the point of cracking. Be sure to use only copper cored sparkplug wire, the modern automotive carbon core wire will not work. The points on almost all models should be completely disassembled and thoroughly cleaned since oil will often have soaked into the insulators causing them to short. Most Johnson models had a point gap of .020” and spark plug gap of .032”. The Johnson ID Chart gives the original sparkplug recommendation, you can cross reference this to a modern plug at the Champion website. Timing on all Johnson outboards in this period will be variable since the magneto plate moves to advance and retard the spark as needed.

Lower Unit & Water Pump

The early Model A and J Johnsons and even the later 1930’s motors used a piston pump with small check valves. The piston must be free to move and the check valves have to be able to do their jobs to have the motor pump water.

Starting in the late 1920’s all but the little Model J single Johnson outboards had a very simple pressure/vacuum cooling system that used the prop wash to force water up into the block and down and out ahead of the propeller. For this system to work all the plumbing must be 100% air tight and obviously there is no tell-tail – your only system check is how hot the cylinders get! Even after other waterpump systems were developed the pressure/vacuum system was used on many of the higher 9, 16 and 22 horsepower Johnson outboards up into the 1950's.

In the 1930's another water pump using an eccentric cam of brass and later a rubber rotor was used on the smaller 2-5hp motors. These have been found to perform well typically with only a good cleaning. Should you need a new rubber rotor for one of the HD or TD series, AOMCI member Bob Long in WA makes replacements - Bob can be reached at the following email address: flyingscott91@yahoo.com. (Bob also makes replacement impellers for newer motors but the old impeller hub must be supplied on an exchange basis.)

Checking the water lines and cylinder water jackets for blockage is good practice. The cast iron cylinders on the early Johnson outboards will often have rust scale that will block water jacket and cause them to overheat. The liberal use of compressed air, picking at the blockage with wire and a lot of flushing are really the only options to fix this problem, short of disassembly of the cylinder and removal of the freeze plugs.

The lower unit should be filled with grease and always checked for accumulated water after each use. Many people like Lubriplate 105 for the lower unit grease, though often something heaver may be required due to the simple seals used on most of these motors.

Fuel System, Oil Mix & Starting

The float type carburetors used on most early Johnson models are simple and reliable. Many times a good cleaning of the bowl and tank is all that is required to put them back in running condition. Due to the corrosive effects of modern gasoline it would be wise to recoat the cork float in the carburetor with a modern fuel-proof coating – discuss this with your local hobby shop owner, they will be able to offer the best alcohol proof solution.

Be sure all fuel fittings are tight and leak free. Most solid fuel lines can be reproduced using copper line and compression fittings still found at hardware an plumbing stores today.

The fuel mixture will vary from model to model, most use a fuel mix of 1/2pt of TCW-3 outboard oil per gallon of gasoline. CAUTION: A few of the budget motors and all the performance motors in the 1930's may require 3/4 and even 1 pint per gallon! Be sure to use a quality regular grade of gasoline, lead free is fine and actually what was originally recommended (then known as Marine White Gasoline). Only use a quality grade of 2-cycle oil marked TCW-3, never use automotive type oils.

The Johnson A, A-25 and many of the other early motors have only a single needle valve. Begin with this at 3/4 to 1 turn open from the lightly seated position and adjust it when the motor starts to the best running position. Once the fuel tap is turned on in a few seconds you should see the needle shaft rise out of the bowl cover. If the motor is cold you can tap the needle a couple of times to 'splash' some raw gas into the carb to assist in starting - don't over-do it, or you will flood the motor. Place the carb lever on 'C' for choke and advance the magneto handle to the center of its travel (See the model ID photo above for the approximate location). If the motor does not start after 3 rapid tugs on the starter rope place the carb lever on 'F' for fast and try 3 more tugs. If the motor still will not run then shut off the fuel tap and continue with 3-5 tugs on the starter rope - once the motor starts be sure to turn the fuel valve back on!

Lost or Broken Parts

Unfortunately, if you have a 1922-42 Johnson outboard you can’t go to your local Johnson dealer and expect any help. The AOMCI Webvertize are free ads and deliver amazing results if you are looking to buy parts or find a good home for an old Johnson outboard. You can also try one of the many on-line auctions like eBay or Craigs List but for our money the Webvertize is better!

Some vendors we have for related parts are as follow, click on the link and it will take you to the website. (Please note we do not have any affiliation with these folks)

Brillman Co.(Ignition supplies)

Otto Gas Engine Works(Stock and custom piston rings)
Champion Spark Plugs(Spark plugs and old plug conversion )

Art DeKalb's Site(Reproduction parts)

Lee Pedersen(Ignition wire and terminals)

American Outboards(Decals)

Bob Long Impellers(Waterpump impellers for TD series and later)

Information for this web-page was obtained from the AOMCI publication FOUR MEN FROM TERRE HAUT by J.M. Van Vleet, THE OLD OUTBOARD BOOK 3rd Ed. by Peter Hunn and from 40 years worth of Bob Zipps' excellent articles on the Johnson A's in the OUTBOARDER (Magazine of the AOMCI). And a special thanks to Bob Zipps for proofing and editing this page!

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