Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 16 of 16
  1. #1
    Cadet
    Join Date
    Jan 2008
    Location
    Illinois
    Posts
    7

    Default Old 3 HP Johnson Sea Horse

    Hi, I just found this forum surfing for some info on my son's 3 HP Johnson Sea Horse. It is a JW-10 which is the 1952-54 model. It starts and runs fine, but the gas cap is cracked and leaks badly when the motor is tipped up. I told him I'd search for a replacement. I'm not doing very well.

    Any ideas would be appreciated.

    Regards, Jim B.

  2. #2
    Vice Admiral samo_ott's Avatar
    Join Date
    Jun 2006
    Location
    Ottawa, Canada
    Posts
    5,092

    Default Re: Old 3 HP Johnson Sea Horse

    I have the exact same engine. This forum is more for help than parts. I would try the www.aomci.org site as they cater to the older engines and the classifieds are pretty good.
    Steve.

  3. #3
    Fleet Admiral HighTrim's Avatar
    Join Date
    Jun 2007
    Location
    Hamilton,Ontario
    Posts
    9,449

    Default Re: Old 3 HP Johnson Sea Horse

    Another useful site for parts for the older motors is "http://www.laingsoutboards.com/newpage4.htm"

  4. #4
    Cadet
    Join Date
    Jan 2008
    Location
    Illinois
    Posts
    7

    Default Re: Old 3 HP Johnson Sea Horse

    Thanks Steve and High Trim.

    I did a quick look at both of those links. They are definitely going to help.

    Steve, you have the same engine. Greg likes all the comments he gets about his. However, he changes the lower unit oil about every five tanks of gas (water gets in). Is that normal? I told him the seals or whatever must not be very good anymore. The link to parts should help with that. Thanks again.

    Jim

  5. #5
    Fleet Admiral HighTrim's Avatar
    Join Date
    Jun 2007
    Location
    Hamilton,Ontario
    Posts
    9,449

    Default Re: Old 3 HP Johnson Sea Horse

    Is he changing the gaskets on the drain and vent screw every time? That is the number 1 spot for water intrusion. If not I would replace them, then run it again to determine if the leak is fixed. If there is still water intrusion, he will need to pressure test to determine exactly where the leak is, or simply replace all the seals. Steve will definately be 1 of the guys to talk to on here about the older motors. Good luck.

    Just for future....

    To pressure/vacuum test a lower unit:

    a) drain the gear oil
    b) use an appropriate adapter with a gauge tee'd in to apply pressure or vacuum. No more than 15 psig for pressure. You can use a bicycle pump or any other compressed air source for pressure. For vacuum, you need a vacuum pump.
    c) LU should retain some pressure or vacuum for 45 minutes minimum.
    d) If pressure doesn't hold, submerge LU in water to find leak source [possibilities: drive shaft seal, prop shaft seal(s) (usually two), shift shaft seal and the fill/drain screw washers.]
    e) replace offending seal(s) as required.

  6. #6
    Vice Admiral samo_ott's Avatar
    Join Date
    Jun 2006
    Location
    Ottawa, Canada
    Posts
    5,092

    Default Re: Old 3 HP Johnson Sea Horse

    I have the engine but actually have not got it in the water yet... it's on a long list of things to do... But for any engine there should not be that kind of water infiltration so do as HT says...

    But in the meantime, changing it regularly is a good thing to prolong the life... also consider using synthetic LU oil (I know it costs more) as it's supposed to work much better than regular oil when it's been compromised with water...
    Steve.

  7. #7
    Cadet
    Join Date
    Jan 2008
    Location
    Illinois
    Posts
    7

    Default Re: Old 3 HP Johnson Sea Horse

    Wow! It looks like I came to the right place. Thanks again.

  8. #8
    DJ
    Guest

    Default Re: Old 3 HP Johnson Sea Horse

    Check Twin City Outboard for a cap. They are on Google. I know they will have one.

  9. #9
    Vice Admiral Scaaty's Avatar
    Join Date
    May 2004
    Location
    West Coast (PNW) Salty Dog
    Posts
    5,099

    Default Re: Old 3 HP Johnson Sea Horse

    GREAT old motors..have 3. Bulletproof.
    I have a good lower (weedless..angle drive) that I switched out on one, for a later straight drive.
    And a day late on a cap..just sold my last one. Keep an eye on Ebay...
    Interested, PM me, or email me .. hogrider@myway.com put 3hp in the sub line.....

  10. #10
    Rear Admiral
    Join Date
    Aug 2001
    Location
    Texas
    Posts
    4,006

    Default Re: Old 3 HP Johnson Sea Horse

    Can't remember what kind of seals are in the LU of those little Johnsons from the early 50's. If it is losing regular marine LU lube/oil regularly, consider using Lubriplate 105 white engine assembly grease instead of the more fluid LU oils. Those older LU seals really weren't engineered for modern LU lube/oil. The Lubriplate will not emulsify with the water and thin and run/leak out. You can find Lubriplate at just about any auto parts store.

  11. #11
    Fleet Admiral HighTrim's Avatar
    Join Date
    Jun 2007
    Location
    Hamilton,Ontario
    Posts
    9,449

    Default Re: Old 3 HP Johnson Sea Horse

    As tmclavary said, the seals are different now than they were in the 1950's. So if he does do the seals dont be surprised to see they are a bit different.

  12. #12
    Cadet
    Join Date
    Jan 2008
    Location
    Illinois
    Posts
    7

    Default Re: Old 3 HP Johnson Sea Horse

    Thanks for all the great info.

  13. #13
    Captain
    Join Date
    Aug 2002
    Location
    Banana River
    Posts
    3,183

    Default Re: Old 3 HP Johnson Sea Horse

    If changing seals make sure to change the one under the waterpump too...and check the shaft surface where it rides. If rough from corrosion it will continue to eat seals.

  14. #14
    Fleet Admiral HighTrim's Avatar
    Join Date
    Jun 2007
    Location
    Hamilton,Ontario
    Posts
    9,449

    Default Re: Old 3 HP Johnson Sea Horse

    Gearcase and waterpump

    help1.jpg

    Carb

    help2.jpg

    Step by step explanation of how to fully tune that motor up. May be useful to you. Good luck. Just copy and paste with the "" ""

    "http://www.maxrules.com/fixtuneitup.html"

  15. #15
    Captain
    Join Date
    Aug 2002
    Location
    Banana River
    Posts
    3,183

    Default Re: Old 3 HP Johnson Sea Horse

    The seals you want to change in those pics are called "oil retainers"...one is on the prop shaft and the other under the waterpump assy.

  16. #16
    Cadet
    Join Date
    Jun 2008
    Location
    central florida
    Posts
    28

    Default Re: Old 3 HP Johnson Sea Horse

    I have the same motor. Please let me know where you have success. Thank you

Similar Threads

  1. johnson sea horse 5.5 horse model CD-10
    By crittercaller in forum Johnson & Evinrude Outboards
    Replies: 8
    Last Post: July 6th, 2007, 09:47 PM
  2. 58 Johnson sea horse 10 horse
    By imported_janice in forum Johnson & Evinrude Outboards
    Replies: 3
    Last Post: July 3rd, 2006, 03:54 PM
  3. 10 horse johnson sea horse QDL-19
    By imported_janice in forum Johnson & Evinrude Outboards
    Replies: 2
    Last Post: July 1st, 2006, 04:55 PM
  4. Year and Horse Power of Johnson Sea Horse
    By sam6868 in forum Johnson & Evinrude Outboards
    Replies: 2
    Last Post: March 30th, 2005, 06:25 AM
  5. Johnson 40 horse HELP!!!
    By Egghead in forum Johnson & Evinrude Outboards
    Replies: 1
    Last Post: July 18th, 2002, 01:52 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic