Evinrude model U

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    2fast4me
    US Member - 1 Year
    Replies: 170
    Topics: 15
    #183498

    Greetings members, Evinrude Model U, not much info out there on this one. I just picked up mine Sunday so I’ll be looking for advice.
    It’s stuck so first order of business will be getting it turning again, it’s soaking in magic juice as i type. Missing some screws on the intake and carb and something loose with the flywheel, not sure yet other than that its complete. I checked in the Inner Sanctum and found an index for the motor but there does not appear to be an electronic copy of the magazine.
    What do i have here?
    Any info is appreciated, thanks.
    Jim

    2Fast4Me

    • This topic was modified 1 month ago by Avatar 2fast4me.
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    wbeaton
    Canada Member - 1 Year
    Replies: 668
    Topics: 74
    #183500

    Sounds like you have a 1929 Evinrude Speeditwin. The carb is cast zinc and very fragile. Be extremely careful when you dismantle it.

    Wayne
    Upper Canada Chapter

    uccaomci.com

    Randy in Tampa
    Randy in Tampa
    US Member - 1 Year
    Replies: 194
    Topics: 19
    #183501

    Early speeditwin , I have two one I believe to be 1930 but I was told it could be a 29 and also a 1931 electric start, hold onto it get running I’m sure if you need parts will be able to find them in this club we all would like to see the motor running and many of us are fond of square tanks, good luck and let us know when you get it unstuck 😉

    Rotary valve Johnson’s Rule!

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    2fast4me
    US Member - 1 Year
    Replies: 170
    Topics: 15
    #183503

    Wayne and Randy, thanks I’m just in evaluation mode with this one and i may soak everything up with magic juice till winter. I don’t want to go backwards with it. I sure wish i could read the old outboarder article.
    Jim

    2Fast4Me

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    wbeaton
    Canada Member - 1 Year
    Replies: 668
    Topics: 74
    #183505

    Was it this article from Jim Smith?

    Wayne
    Upper Canada Chapter

    uccaomci.com

    Attachments:
    Tom
    Tom
    US Member - 1 Year
    Replies: 380
    Topics: 39
    #183509

    The U Speeditwin came out for the 1928 model year, and had an above water muffler. The ’29 had a number before the U, and had underwater exhaust. Which does yours have?

    The ’28 U series had roller bearings on the main and crank pins, I think that was the first year for Evinrude to do that. Coils are shared with opposed twin Evinrudes of the same era. Some of the Fastwin 12 and 14 hp motors of ’28 and ’29 had aluminum hubbed flywheels, which didn’t hold up well. If yours has a steel hub riveted in, all the better. And like mentioned above, carbs and air horns are getting hard to find.

    The cooling system works on a vented propeller. When spinning, the vacuum generated at the outlets of the prop pull cooling water up through the motor, then back down. For this to work, the water tube connections need to be airtight or nearly so. The original tubing and compression nuts were aluminum. Many have been replaced with copper. The compression nuts are NOT the same as those you can purchase today. So if there are copper lines or brass compression nuts on your motor, you’ll need to do some work. There are two V-shaped fittings on the back of the motor. One is supply, one is return. I’ve seen these set up backwards, so water enters the top of the cylinders and returns through the bottom fittings. Be sure yours isn’t set up this way. IIRC, the top V-fitting is the supply, the bottom is the return, but check that with some compressed air.

    Be sure the cotter pins which retain the wrist pins are intact. Once unstuck, inspect the pistons carefully to assess their condition. Broken ring lands are not uncommon in my experience.

    Good luck with the motor, these sound GREAT when they’re running!

    T

    tinkerman
    tinkerman
    US Member - 1 Year
    Replies: 105
    Topics: 18
    #183529

    Not trying to hijack the thread but this is good info for others as well. I also have a “u” model I will be starting on before long. 1928 or 29, can’t remember off top of my head.

    Happy is a place we visit from time to time, content is a place where we can spend our life

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    garry-in-tampa
    Lifetime Member
    Replies: 3204
    Topics: 30
    #183530

    The ’29 racing model had dual carburetors. The last time I saw one raced was in 1950. It finished fourth in a field of twelve. Dad remarked that the connecting rods must really be getting tired by now. The first attempt at a “full jeweled” powerhead. A well set up model is not hard to pull over. You bounce it against compression to get a flying start on the pull.



    Avatar
    2fast4me
    US Member - 1 Year
    Replies: 170
    Topics: 15
    #183532

    Tom,
    1. Above water muffler.
    2. No # before the “U”.
    3. Steel hub on flywheel, steel hub riveted to aluminum flywheel.
    4. Vented propeller-don’t know yet. Top of cylinders have copper fittings that do not connect to anything and no evidence of a 2nd “Y” pipe but i am still looking. I’ll try to get pictures later.
    Thanks everyone!
    Jim

    2Fast4Me

    Tom
    Tom
    US Member - 1 Year
    Replies: 380
    Topics: 39
    #183534

    OK, so it appears you have a ’28 Speeditwin. I believe that one has an impeller pump in the front of the lower unit, not a pressure / vac system and vented prop. The water just dumps out the top of the cylinders through short pipes.

    Sorry for any confusion.

    T

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    george-emmanuel
    US Member - 1 Year
    Replies: 376
    Topics: 19
    #183565

    Tom gave some great knowledge! The compression fittings are about .050 undersize. If you use modern versions they will jump thread as you tighten. I made all new ones on the lathe for a ’28 H Fastiwn I built.

    The U in my opinion is a lazy starter. By that I mean it seems to start really rich and finally clears out. I’ve always felt the venturi is too big. One day I hope to try a Speedifour carb.

    Tom is right on about those cotter pins in the wrist pins. Don’t use a slightly undersize cotter pin because it’s easy to install! Use a full size. I found that some have alignment issues with the holes on the piston’s wrist pin boss and the wrist pin holes. I did one and used an aircraft drill (needed for the length). I lined up the top piston hole with the wrist pin holes and ran the drill through to bring the bottom piston hole into alignment. I have seen 29 U’s using wrist pin clips!

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    2fast4me
    US Member - 1 Year
    Replies: 170
    Topics: 15
    #183618

    Oooookay I cleaned the model “U” and preformed an autopsy to find out why it died 50 years ago, well it may have died long before that but the guy i bought it from had it since 1970. I’m amazed people keep things as long as they do, kindred spirits I think.
    Well it is stuck and the pistons are near the top and the ports are open to the crankcase so i have Some debris in the crankcase and the rings show rust. I think it best to fill the crankcase with penetrating oil and let it sit, maybe even some 16/1 mix, any thoughts? Some people swear by acetone and ATF some swear at it.
    I cleaned the carb, air horn and manifold and found one mixture screw missing and the top of the float Bowel slightly cracked at a screw hole. I have a plan for that.
    Gas tank has two small holes. Not worried yet!
    I pulled the flywheel and cleaned everything, no parts missing. I did some polishing also.
    Getting it unstuck is a priority if it won’t i may just cosmetically restore. I’ve got pictures, but it’s late. Thanks for all the help!
    Jim

    2Fast4Me

    bobw
    bobw
    US Member - 1 Year
    Replies: 640
    Topics: 28
    #183619

    If it’s showing rust, I’d fill it up with some Evaporust or Metal Rescue first to knock out the rust. Drain that off, then follow up with the penetrating oil. The 50/50 acetone/ATF does makes a good penetrating fluid.

    Bob

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

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    rapier
    International Member - 1 Year
    Replies: 98
    Topics: 25
    #183677

    Thanks for the input on this post. Will be a great help to me when I get to my 16hp and 20hp model Us.

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