1954 big twin

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This topic contains 18 replies, has 11 voices, and was last updated by Avatar Tinman 1 week, 3 days ago.

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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #184939

    Hello every. I have a 1954 25 hp evinrude. it’s all there. Electric start. Brass prop. Actually in pretty decent shape overall. Need to check compression but roping it over is a tough go. May have to hook up the starter for that. Was thinking about making it a winter tune up project. Anything to look out for or is it pretty straight forward tune up procedure? Haven’t have much experience with anything larger than an 18 hp. Thanks.

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    2fast4me
    US Member - 1 Year
    Replies: 170
    Topics: 15
    #184945

    Take pictures before disassembly, you will need them. Keep your removed items bagged and tagged for proper reassembly. Some long bolts in the wrong location can cause cracks and broken components. I haven’t gotten into my powerhead yet so if you need pictures? Just ask. There is a lot going on with the throttle advance on that one. Jim

    2Fast4Me

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    crosbyman
    Canada Member - 1 Year
    Replies: 1239
    Topics: 161
    #184948

    if you dont have this go to the url on top !!

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    garry-in-tampa
    Lifetime Member
    Replies: 3205
    Topics: 30
    #184958

    Since it has the same magneto as the 18, you already know about checking the coils . . . You will find it much louder than he 18 as it does not have the rubber mounts and enclosed powerhead like the 18. The remote controls may have to be lubricated as the lithium (white) grease tends to dry out with age.

    David Bartlett
    David Bartlett
    US Member - 1 Year
    Replies: 167
    Topics: 8
    #184962

    I have a 1954 Johnson 25. One of my favorite motors. With the plugs out it will pull over fine to check compression.

    The cable operated throttle and spark advance is a bit different than the later engines, but works well. If you don’t already have one of Richard Whites timing tools, I really recommend you do. This motor will really start better and run nice when the ignition is spot on.

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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #184963

    I have one of his timing tools. I use it on 5.5-18 hp. Does it use the same tool or do I have to purchase another one? Thanks for all the replies everyone.

    frankr
    frankr
    US Member - 1 Year
    Replies: 4471
    Topics: 43
    #184964

    Unfortunately, it takes a different timing tool.

    RICHARD A. WHITE
    RICHARD A. WHITE
    US Member - 2 Years
    Replies: 1645
    Topics: 130
    #184965

    That model uses the tool I have labeled #4 Timing Tool

    http://www.richardsoutboardtools.com

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    jeff-register
    US Member - 1 Year
    Replies: 1129
    Topics: 47
    #184968

    If parts are around I would reseal the gears & impeller. Is that one a 6 volt system? Very nice motor!!
    P,S,
    Have the service manual if you need pages e mailed

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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #184975

    Thanks Richard. #4. Got it. And yes it’s a 6 volt system. And jeff, yes I would like the service manual. Thank you.

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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #184977

    I got home and checked compression. 85 top and bottom. Is that good enough to proceed? Not sure where those # should be on a 25 hp. And they may improve once its running.

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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #185017

    Does anyone know if the compression numbers are ok? Thanks.

    bobw
    bobw
    US Member - 1 Year
    Replies: 640
    Topics: 28
    #185021

    85 is a little low but it should run. I’d run it with some fresh gas and oil and some Engine Tuner or other decarbon product and see if that might loosen up some sticking rings and let the compression come up some. You may also have a bad head gasket.

    Bob

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

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    fleetwin
    US Member - 2 Years
    Replies: 2753
    Topics: 33
    #185022

    Well, 85PSI seems a little low for that engine, but you are cranking it by hand, which is tough….I would definitely rig up some jumper cables to you can crank it with the electric starter… Originally, this was a 6 volt system, but who knows what is in there now…Have a look at the starter, perhaps it will say. You can use a 12 volt battery on the 6 volt starter, provided you don’t crank it for too long a period. But, using the 12 volt battery on the choke solenoid will damage that part. Sounds like this engine is in nice original condition, all the wiring/junction box is there also? If so, you surely don’t want to damage any of those pieces…An electric start big twin from that era is quite a bit more rare than the standard recoil model. For must of us old cranks, the electric start is a much needed option….
    So, recheck compression using the electric starter…
    Pull the flywheel, do you have the OMC puller unit? Please don’t attempt this using some alternative puller, damage and injury can result. The ignition will surely need to be completely serviced unless someone has been in there recently…
    Drain/refill the gear lube? Is the gear lube relatively clean, free of water? Older lubes were pretty dark in color so that is normal. Milky colored gear lube is an issue, raw water spells trouble. You should probably pull the gearcase and replace the water pump impeller.
    The carb should be disassembled, cleaned and rebuilt as well, unless there is evidence that someone has done this work and used more up to date gaskets/etc. Finally, do you have decent pressure tank? Open the cap, have a look inside…A badly fouled/rusted tank is useless….
    Feel free to post pictures with any questions you have, makes it easier to understand what you have so we can provided more useful advice/answers…

    • This reply was modified 1 week, 3 days ago by Avatar fleetwin.
    • This reply was modified 1 week, 3 days ago by Avatar fleetwin.
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    Tinman
    US Member - 1 Year
    Replies: 157
    Topics: 29
    #185037

    It’s all original. 6 volt. I have a 6 volt battery so no worries there. Going to haul it to the garage soon to start looking it over real good. I also have many clean pressure tanks so that’s never a problem. Pick up every one I can find!! It is a bear to eope over by hand so I will hook up the starter and check again. Did they originally come with brass props or is that an aftermarket item? Sorry for less than good pics. Motor is in my barn.

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