gas oil ratio for a 1968 Johnson 15hp electric start

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    Jim Potts


    Replies: 6
    Topics: 2
    #237694

    Hello,
    I just purchased a 1968 Johnson 15hp electric start outboard motor. I have a couple of questions:
    1. what is the oil to gas mixture ratio?
    2. does anyone have the starting procedures for this electric start motor. I bought it without starting it because it was just a throw-in with the boat and trailer.

    thank you!

    Jim

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    crosbyman

    Canada Member - 2 Years
    Replies: 2054
    Topics: 225
    #237695

    50/1 usually in those years

    before you start it

    check or better yet replace the impeller …. change gearcase oil and check for water intrusion if you have water you will need to reseal the GC … use new nylon washers when closing it up

    pump it up with fresh gas and try it out … check water pump operation you may need a carb job (not complicated) if rough

    post mdl #…. I found no 1968 15hp Johnson listed

    Joining AOMCI has priviledges 🙂

    • This reply was modified 1 week, 4 days ago by Avatarcrosbyman.
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    Jim Potts


    Replies: 6
    Topics: 2
    #237701

    Thank you! I’ll check to make sure I have the year right.

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    crosbyman

    Canada Member - 2 Years
    Replies: 2054
    Topics: 225
    #237703

    see listing for 15hps

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    Jim Potts


    Replies: 6
    Topics: 2
    #237717

    yes, you are correct. It’s a 1956 Johnson 15hp electric start. So it must be the E-10. Besides the helpful info you shared on what to do before trying to start the motor. What about the actual steps for starting it? Choking, throttle, push button, etc. All the outboard motors I’ve started in the past have been manual pulls.

    thanks again.

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    Jim Potts


    Replies: 6
    Topics: 2
    #237718

    Apologies to everyone, the correct year of my motor is 1956.

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    Jim Potts


    Replies: 6
    Topics: 2
    #237719

    and with a 1956 year motor; still 50:1 gas to oil mix, right?

    bobw
    bobw

    US Member - 1 Year
    Replies: 1383
    Topics: 46
    #237720

    Nope. If it’s a 1956 model, correct mix is 16:1. Some will tell you that you can get by with 20:1 or 24:1 but I think it best to stay with original factory recommendations.

    Bob

    1954 Johnson CD-11
    1956 Johnson RD-18
    1958 Johnson QD-19
    1959 Johnson QD-20
    1957 Evinrude Fastwin 18

    "Every 20 minute job is only a broken bolt away from a 3-day project."

    • This reply was modified 1 week, 4 days ago by bobwbobw.
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    crosbyman

    Canada Member - 2 Years
    Replies: 2054
    Topics: 225
    #237724

    if you have a pressure tank system … keep the lid shut so pressure can build up in the tank to feed fuel up to the engine…

    fill the carb by pumping the tank button 5-10 times

    typical you have a electric choke push button for the electric choke so just push it while starting the engine release it when started throttle in neutral always

    btw great engines…pamper it oil it as per specs !!

    Joining AOMCI has priviledges 🙂

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    JOHN HOLBIK


    Replies: 120
    Topics: 2
    #237733

    Johnson made a 15hp around 1968 it was called a Percheron I know this for a fact as one of our customers at our resort brought one and I guided him for the week.The motor ran well and trolled great I believe it was a one year offering I also saw it in an advertising brochour back in the day.It had a hood on it that looked just like the Gale 15 from the early 60s.Maybe it was only avalible in Canada they called it a work horse model.
    We ran all our outboards from 1952 to 1964 on 25 to one and the later ones on 50 to one all of our motors had thousands of hours on them I have a 56 Johnson 15 hp it is my favorite engine it has a gazzlion hours on it and it runs perfect..
    Our mix system was simple one 5 gallon milemaster tank one quart oil for old motors.
    1 5 gallon milemaster tank for newer 1 pint oil we never went with the later omc 100 to one.

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    fleetwin

    US Member - 2 Years
    Replies: 3775
    Topics: 38
    #237737

    I too, would stick with the original oil mixing specs… And yes, OMC did offer some sort of 15hp around the mid to later 60s.
    Your 1956 15hp electric start may use a 6 volt battery though, not sure.
    What kind of condition does this engine look to be in, can you post some pictures?
    If you plan on using this engine frequently, it is best to go through all the systems thoroughly, so it will be a reliable daily runner…
    For now, let’s start with compression, spark test, and draining/inspect lower unit lube…Do not remove the little phillips screw on the bottom of the gearcase skeg, or the internal shifting linkage will come apart. Remove the big fill drain screws above (or just below) the AV plate (horizontal fin above prop), and the other one on towards the bottom of the skeg.
    Hopefully, you will see relatively dark gear oil drool out slowly. Milky colored lube, raw water, or nothing at all draining from the gearcase spells trouble…
    Let us know what you find…

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    crosbyman

    Canada Member - 2 Years
    Replies: 2054
    Topics: 225
    #237740

    …..must be a E10…. but is it a E10… that is the question 🙂 do you see a name (mdl) plate somewhere….

    by the way as a AOMCI member you could get yourself a free copy of the Jonson maintenance manual (691 pages) to pamper your … E10 for years to come plus any other oldy (early 4os to late 50s) you pick-up 🙂 now that you have the oldy virus.

    Joining AOMCI has priviledges 🙂

    • This reply was modified 1 week, 4 days ago by Avatarcrosbyman.
    • This reply was modified 1 week, 4 days ago by Avatarcrosbyman.
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    Buccaneer
    Buccaneer

    US Member - 1 Year
    Replies: 4605
    Topics: 790
    #237752

    Percheron

    I hear those Percheron’s were real work horses 🙂

    Prepare to be boarded!

    Avatar
    Jim Potts


    Replies: 6
    Topics: 2
    #237755

    Hi everyone,

    I know I confused everyone with the title “1968 Johnson 15hp electric start motor” on this thread. My motor is a

      Johnson 1956 electric start (E10)

    :

    My questions are:
    1. What is the oil to gas ratio for this year and model
    2. Does anyone have any contacts for someone who could paint the engine shroud in the original colors?

    thanks again to everyone for their advice and help.

    Jim

    Mumbles
    Mumbles

    Canada Member - 2 Years
    Replies: 4894
    Topics: 268
    #237758

    The factory required oiling for your ’56 Johnson FDE-10 is 24:1. Nothing else. These one year only fifteen horse motors have roller bearings throughout in them except on the small end of the connecting rod and were the basis for the later 18, 20, and 25 horse motors. Gale built 15’s used the same non thermostat equipped powerhead thru ’63.

    Here’s a parts manual for you.

    1956-Johnson-15HP-FDE10-Parts

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