Johnson

Johnson, Evinrude, OMC, outboard motor, outboard motor repair, outboard troubleshooting, 6 hp, water pump, carburetor,

Maintaining 7 1/2 hp, Evinrude Fleetwin /Johnson AD series
2 cycle Outboards

1950 – 1958 (General Repairs)

1952 (2nd year of production

One thing that I want to convey here is that I write only on motors that I have actually worked on, and over a period of MANY years, consisting of many THOUSANDS of hours, and then more in maintaining/updating them. These articles are motor specific, HOWEVER if you are having a diagnosis issue, my Trouble Shooting article covers MANY more aspects that may help you diagnose your issue. CLICK HERE for access to that article.

You do not see that many of these little motors, probably because of the limited production. The rather rare of these model would be the Johnson, which was only made for 3 years (after the merger of Evinrude and Johnson) under the the OMC production.

If you see any indication in this article pertaining to Right hand or Left hand, this will be determined as if you were standing at the rear of the motor looking forward.

Year of Manufacture : This is important in any repair, for obvious reasons. These 1950-1958 They were made in standard 15" shafts or long 20" versions from the beginning. These Evinrude model numbers started in 1950 as model 4434. This same motor in a (20") longshaft would have been 4435. The Evinrude model designations are confusing to say the least.

Even though longshaft motors were made, finding one of this series would be quite rare, as in those days most of these small motors were used on small fishing boats and not as kicker motors for larger fishing boats which in most cases require the longer shafts.

There should be the model and serial number on riveted on 1” X 2” aluminum ID plate on the LH side of the transom mount bracket (looking forward). Sometimes this ID plate can get removed.

   In this listing below the second model number equates to a longshaft
               Evinrude 4434/4435 = 1950

                   Evinrude 4443/4444 = 1951
               Evinrude 4447/4448 = 1952
               Evinrude 7512/7513 = 1953
               Evinrude 7514/7515 = 1954
               Evinrude 7516/7517 = 1954
               Evinrude 7518/7519 = 1955
               Evinrude 7520/7521 = 1956                Johnson AD-10
               Evinrude 7522/7523 = 1957                Johnson AD-11
               Evinrude 7524/7525 = 1958                Johnson AD-12

    This motor shares many parts off the 5.5 and 6 hp motors of the same/near area of production.

These motors develop 7.5 hp @ 4000 RPM
Cylinders               2
Bore diameter      2.120"
Stroke -                 1.750"
Displacement        12.4 CI
Starter -                automatic rewind
Bearings -             bronze bushings, both mains & rod
Carburetor -         OMC, metal float type

Choke -                  Butterfly, pull knob
High speed jet,     Adjustable
Idle jet -                3/4 turn out

Throttle Control - Side lever on early, twist grip on later
Fuel capacity -      integral on early motors, remote tank on later ones
Fuel/Oil mix is       (24:1)
Point gap is          .020"
Plug gap -             .035", Champion J6C or J8C spark plug.
Flywheel key -    Woodruff .153" wide x .235" thick x .603" long ?
Flywheel nut -    3/4" wrench ?
Water Cooled -    Rotary vane water pump   Sierra #18-3001
Gearbox oil -       90 W gear oil
Gear Ratio -          ?
Prop. dia. & pitch- - 3 Blade, LH, 8" X 7 1/2" with 1/2" bore ?
Shear Pin -          1/8" (.125") diameter X 1.250" OAL?
Prop nut retainer pin - 3/32" X 1"  ?
Prop nut -            special nut, 7/16" X 20 TPI ?
Paint Color -
Weight -               56#