Late 70's Johnson 70Hp wont charge?

Discussion in 'Bubba's Outboards' started by 01 Mudslinger, Jun 11, 2007.

  1. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    I have i believe its a 76 thundercraft with a 70Hp Johson Outboard, ive had the boat just a little over a year and put a new battery in it when i got it and have never had any problems with dead batteries, well the other day the battery was dead, went out fishing that nite and when it was time to leave the battery was dead, luckily i took a back up battery, Where should i look to figure out what is wrong with it? Alternator? does a boat have a alternator? Im a little lost on this one, dont know alot about it, so a general direction to get me started would be appreciated. thanks guys
     
  2. pat muckelroy

    pat muckelroy New Member

    Messages:
    35
    State:
    texas
    The best deal is take it to a boat mechanic and he will fix it without guessing. If this is not possible, charge the battery up and get a volt/ohm meter from the local car parts store and check the voltage in the battery. Lets say it measures 12 volts. Run your motor with water hooked up to it and measure the voltage at the battery posts again. If it is less, your charging system is not working. Check for a loose or broken wire around the motor. Check for a fuse blown if you have a gage and a fuse panel. If nothing is visible, take it to a mechanic. Pat Muckelroy
     

  3. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    I'll post the recetfier test in a little while I am busy right now and you can save yourself 100.00 for the marine tech to tell you what you can find for your self and it won't be guessing either.

    Side note do not remove the battery cables from the battery of an outboard while it is running. it doesn't work like a auto and yes it does have an alt.
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Remove leads from Rectifier.
    With an Ohm meter, place the Red lead on the
    + Terminal on the Rectifier.
    Place the Black lead on the AC Terminal
    Repeat the above steps for both the AC Terminals.
    The Ohm meter should show continuity.


    Not Shown

    Remove leads from the Rectifier.
    With an Ohm Meter, place the Red lead on the
    AC Terminal on the Rectifier.
    Place the Black lead on the - Terminal
    Repeat the above steps for both the AC Terminals.
    Continuity should only be read 1 way.
    If it reads both ways, the Rectifier is BAD

    Please Note.

    If you have a Johnson or Evinrude, Yellow wires
    will be the equivalent of the AC Terminal and the red will be the +
    They are tested the same way as the tests written here.


    This is giving you the test for two different recetfiers. I'll post a picture in a few of what yours should look like
     
  5. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Hunter, listen to BubbaKat. He has all ready saved me hundreds. If the rectifier is bad, should run about $45.00 to $50.00. If its the stator, they go up to around $125.00, I believe. And that is about all there is to the charging system on an Evinrude/Johnson.
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Hunter after the check and it does turn out to be the recetefier then the part number is 18-5708 and is about 28 bucks plus shipping.
    You can try your local napa store with that number and see what their price is. I am going to add a picture you look at yors and see if they look alike.


    The wires should be 2 yellows and a red if not let me know and I will go out and look at mine.
     
  7. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    ok thanks alot for your help, i really appreciate it, heres what i come up with, i pulled the rectifier off, it has 2 yellow wires, and a heavier insulated black wire, that black wire is cracked in 2 places and the wires are all corroded and rusty and somewhat broke apart, i done the test and i believe i done it right, i got a reading of 513 on one yellow wire and 511 on the other yellow wire, so reading your instructions since i got a reading on both wires that means the rectifier is bad, Correct? Regardless im gonna replace it since its all corroded and rusty, but just wanna make sure i done the test right, i like learning new things when it comes to being able to work on the boat.
     
  8. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Yep bad one you have there. I like a person that likes to keep his equipment up to top shape. If you need me to PM you a site contact where you can order that part then let me know. I also have the test procedures for a lot of components on that engine. Feel free to ask away.
     
  9. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    thank you a whole lot man, i really appreciate the help, yes if you could direct me to some places that i can find the part it would help alot. thanks again.
     
  10. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Hunter how is this problem coming along?
     
  11. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    Hey sorry i missed ya checking up on me, i called napa earlier and they said that 18-5708 was a 6-8 amp charge and made for a 100-110-115 Hp Johnson, but like u said was priced at $39, the one listed for my motor was $165 that they had, so i can buy the 5708 part and it will work on my motor? and get by with on around $40 bucks to fix it? Just making sure before i head over to buy it. Thanks Again
     
  12. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Hunter post the model number of that engine and let me check. I think the napa man was wrong or reading out of a super man mag.:big_smile:
     
  13. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    aight ill get it in the morning, It should be on the motor somewheres right?
     
  14. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    It should be on the transom mounting bracket.
     
  15. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    Model # 70EL76D

    Serial # J4534731

    Thanks Again.
     
  16. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Hunter does your rectifier shape is round or retangler shape.
     
  17. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    Its round, identical to the one you sent in the picture
     
  18. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    After a lot of research on that engine That part number was superceded so many times I ran out of room on my scratch pad.:lol: But after all the searching that 18-5708 will work on that engine and I can give you a link and you can order it for 28 or 29 bucks plus shipping.
     
  19. 01 Mudslinger

    01 Mudslinger Member

    Messages:
    264
    State:
    Gretna, Va
    Thanks alot man, i really appreciate the fact that u will take time out of your schedule to help me out. not alot of people like that these days, ill probably just go ahead and get it at napa that way i can get the boat goin for this weekend. Thanks again man, oh yea one more thing, i didnt think to pay attention to which terminal each of the 3 wires came off of, so i may need alittle help hooking it back up.
     
  20. emptyhook

    emptyhook New Member

    Messages:
    44
    State:
    north carolina
    bubbakat, i recently purchased this 6hp. evinrude. can`t get an exact
    age on it, or answer about a small but noticable oil leak,[black looking]
    that leaks out in the seam below gearbox on lower unit.when i tilt it up
    for transport. any advice or help greatly appreciated.

    mod# E6RCOB

    ser#.B101525