tachometer malfunction

Discussion in 'Bubba's Outboards' started by weathermantrey, Dec 21, 2005.

  1. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    Just took my pontoon out, and my tachometer went crazy for about 20 seconds, then started smoking. Could it be because I didn't have a battery hooked up to the boat while running it? I dont understand why it would just up and burn out like that.
     
  2. Koda

    Koda New Member

    Messages:
    39
    State:
    Tombstone,AZ
    not sure about ypur chargeing system but on mine if there is not a battery connected there is not much regulation on the alternator out put so the voltage can go wild, the perko switch instructions state that you need to shut the engine down prior to shutting off both batterys to prevent damage to the electronics on the motor.
    Luck David
     

  3. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    I would say if you didn't have any battery hooked to it . Most likely your rectifier overloaded it and cooked it. Most likely the rectifier to.
    I have seen then burn the stator out from under the fly wheel to.

    If you will tell me what motor you have I will post a test for the rectifier for you.
     
  4. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    it's a 1983 evinrude 70 h.p., thanks
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Have you ever run it before without a battery?
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    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.
     
  7. weathermantrey

    weathermantrey New Member

    Messages:
    516
    State:
    central,sc
    I tried to do the rectifier test, and it seems it is working fine. I took the boat last week and hooked it up to a dead battery, jumped it off, and after 10 minutes of running it the battery was fully charged. However, After about 10 minutes of going down the lake there was a little smoke coming from the box where the gas throttle mounts too. Like maybe something inside was getting too much power...and a wire was metling or something. so my question is.. if my rectifier is ok, what's causing the throttle box to smoke.
     
  8. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    You need to get into that control box and find the pinched/shorted wire.
     
  9. klemsontigers7

    klemsontigers7 New Member

    Messages:
    101
    State:
    SC
    will a battery charge if the rectifier is bad?
     
  10. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    The rectifier's full nomenclature is rectifier/regulator. No the battery won't charge. First indication that the r/r is bad, if your not using a tach.