what does the kill switch do?

Discussion in 'Friction Drive' started by motman812, Feb 9, 2015.

  1. motman812

    motman812 Member

    Hi, My Staton friction drive has been having an intermittent electrical problem. Out of the blue it would not start from a lack of spark. After fooling with the connection on the line from the engine to the switch and the switch itself the engine started and ran fine, until it did it again. What exactly does the kill switch do; ie does it make an connection to the frame to kill the engine when it is switched "off"? Any help will be appreciated. Thanks.

  2. darwin

    darwin Well-Known Member

    It interrupts the juice flow between the pickup and cdi. Is your kill switch 1 wire or 2 wire? 1 wire will ground through the frame/motor, 2 wire will ground through the return wire to the motor housing usually.
  3. wheelbender6

    wheelbender6 Well-Known Member

    The kill switch allows you to quickly turn off the motor if you get a throttle stuck open or other such situation.
  4. motman812

    motman812 Member

    kill switch

    Thanks for the reply, Darwin.
    So if it is one wire it must be shorting when it is switched "on". Should I change the switch and if so is it one that is a closed (connected when it is "on") type switch?
  5. KCvale

    KCvale Motorized Bicycle Vendor

    All a kill button or switch does is short the Mag output to ground.
    You can do it with anything from anywhere.
  6. motman812

    motman812 Member

    So if it is disconnected (there is a small one wire plug between the engine and the switch) or the switch fails the engine should run?
  7. KCvale

    KCvale Motorized Bicycle Vendor

    One side of the switch is connected to ground, that wire is a hot mag wire.
    The engine will not start if that wire is grounded.
    So yes, a bad switch will do it, just unhook the wire.

    I take my motor switch off and use the throttles kill button wired to that that engine wire to kill the engine.
  8. motman812

    motman812 Member

    Thanks for the reply KC. So if my engine has an intermittent spark problem/failure it might not be a faulty switch (accidently grounding the mag wire) but might be the magneto or whatever produces spark in my Honda 35cc engine. I've had it since 2008 and ridden something like 5000 miles (500 hours?) mostly at WOT, is it time for something electrical, like the magneto, to fail? Thanks
  9. KCvale

    KCvale Motorized Bicycle Vendor

    I am not familiar with that exact engine, only that kill buttons and switches ground the output opposed to being in-line between the magneto and CDI, you want every milliamp the mag can produce direct to the CDI for amplification to spark voltage.

    I would suspect a bad plug wire, cap or plug before the CDI, magneto, or the spinning magnet that powers the mag.
    Yes, magnets can loose their magnetism over time.
    Rare, but I've seen it.
  10. motman812

    motman812 Member

    Thanks for the help KC. You're right, it just about always better to assume easy solutions rather than more complicated ones. I'll look into those other items. Thanks again.
  11. gator joe

    gator joe Member

    I agree it sounds like its shorting out somewhere. It could be a bad switch ot a bad wire or bad connection but something is definitely causing it to short
  12. KCvale

    KCvale Motorized Bicycle Vendor

    or causing it to open (bad plug cap, plug wire), either will kill the engine.