ignition trouble maybe??

Discussion in 'Electrical' started by ORTIGO, May 11, 2010.

  1. ORTIGO

    ORTIGO Member

    26
    0
    0
    curious if anyone would know what makes a bike only fire when I let go of the start button? It flat out wont fire until I let go. 89 sportster 883
     
  2. shovelrider

    shovelrider Member

    49
    0
    0
    Sounds like you have a faulty kill/start switch.
     
  3. ORTIGO

    ORTIGO Member

    26
    0
    0
    could be they are original
     
  4. Hoople

    Hoople Account Removed

    7,198
    0
    34
    How did you determine that is whats happening.
     
  5. ORTIGO

    ORTIGO Member

    26
    0
    0
    When I try to start the bike it doesnt matter how long I turn it over. It only fires up and runs when I let go. Sorry to mislead I havnt actually pulled the plugs while trying to start. I will if you think I need to.
     
  6. Hoople

    Hoople Account Removed

    7,198
    0
    34
    I am working without a schematic so I am only guessing. Since your bike is a 1990, was it a points ignition system or were they solid state by then? If it is a points system, it is very possible your ignition system uses a ballast resistor on the primary side of the coil. If it does, in most cases the ballast is by-passed during cranking in order to hop up the secondary output of the coil. Sounds like that may be the case here. If the circuit that bypasses the ballast was failing, you would have exactly what your experiencing.

    Could tell you a lot more if I had a schematic.
     
  7. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

    8,176
    98
    16
    What Hoop is referring to is a holdover from the old 6V/12V days (anybody remember that). Originally old Ignition systems were designed for 6V operation, 12V was a cost reduction, simplification of the starting system to have more power available and less massive components using less current with less loss (Ohms law...more voltage, less current and resistance losses for given power, with the wiring no longer the diameter of you thumb, more like your little finger).

    Of course the problem was, once running, that efficient 12V makes more voltage available for starting mode, but too much in running mode, being hard on points life with ignition system portion of the design still geared for 6V operation continuous running. The ballast resistor would be switched in once the starter had spun engine to life with ignition extra hot, but then put into "Run mode" with ballast resistor in..to save those points from arcing and burning.:D
     
    Last edited: May 11, 2010
  8. Hoople

    Hoople Account Removed

    7,198
    0
    34
    NewHD,,, Stop Stop your giving away my age. I bet I can go out to the garage and find a ballast resistor and a set of points out of something I drove 30 years ago. The days when "points, plugs & condenser" was a tune up! :p
     
  9. ORTIGO

    ORTIGO Member

    26
    0
    0
    lol I remember the tail end of those days, Thanks for the comments guys.
     
  10. Jack Klarich

    Jack Klarich Expert Member

    18,544
    153
    399
    Yeah I too remember ballast resistors if you owned a Chrysler you had a spare in the glove box, most ignition systems today have a resistor wired in the ignition wire