85 hp johnson questions

Discussion in 'Bubba's Outboards' started by willcat, Sep 28, 2008.

  1. willcat

    willcat New Member

    Messages:
    2,463
    State:
    texas
    does anybody know what could be wrong w/ an 1968 85 hp johnson? If you let it run in the bucket it will thru a full tank of gas no problems, but if you get it on the lake, after about 25 or 30 minutes it will shut down and the battery will be dead so you cant get it running again. Supposedly the guy i got it from said he had somebody look at it and he told him the powerpack is out. Now the 2 yellow wires coming from the stator are real brittle and they run to the rectifier. Where those are coming from the rectifier the insulation is all gone & the wires are touching together. Is this why it wont charge the battery???? I bought it for my father in law on an 18 ft glasstron boat and we are trying to get it running good to give it to him for his birthday, any suggestions would really be helpful. Oh yeah the serial# is j2984227 and the moel# is v4al-20a thanks for any & all input!!!!
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Will those wires are going to have to be coated with liquid tape tp prevent them from arching out and burning the other wireing out. tHE Recitfier is most like ly burned out.
     

  3. willcat

    willcat New Member

    Messages:
    2,463
    State:
    texas
    Thanks for the reply glad to see you up & about so quick, hope all is well. Do I just need to replace the rectifier or do you think the power pack is out too? The guy said they never tried to use the pull rope to see if it would fire up again they just hauled it in. But he did run it in the bucket & it ran just fine, idled real good too, it has super quiet on the bottom by the cavitation plate, I guess that's why it sounded really quiet..lol
     
  4. tbull

    tbull New Member

    Messages:
    3,318
    State:
    SW Ohio
    I am kind of in the same boat, the only thing I can tell you is to replace the rectifier and see if your batteries are charging while you run, as far as the power pack I have no idea, cant give advice for something I cant figure out myself...LOL:smile2: See below for rectifier test, this may help you it did me:

    [​IMG] Small Rectifier Test, by Joe Reeves
    Perhaps your engine does not have the water cooled regulator/rectifer but rather incorporates the smaller 3 wire rectifier which sits just forward of a vertical electrical strip on the starboard side of the engine.

    If so, a failed rectifier would knock out the tachometer. See the following.



    Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.

    Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.

    Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

    Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.
     
  5. willcat

    willcat New Member

    Messages:
    2,463
    State:
    texas
    I ordered the rectifier from marineengine.com, should be here friday and we are gonna run it in the lake to see what happens...he saw us working on it so we had to tell him it was his & gave it to him early!!!! He loves it, it was a 1 owner boat and aside froom this it is really a clean boat, the only other thing was the metal tank is gumme d up so we disconnected it & are gonna use portable tanks instead...