Headlight is Killing motor

Discussion in '2-Stroke Engines' started by Gimmick, Aug 4, 2008.

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  1. Gimmick

    Gimmick Guest

    Help, after a year of faithful service, suddenly my headlight is acting as a kill switch for my engine...any light i hook up is doing this. and i am befuddled. It never did this until the other morning, then it stopped....then it started again, no matter what i try any light bulb i hook up seems to ground the system out...any ideas as to what the cause and cure for this may be...

  2. JemmaUK

    JemmaUK Guest

    It might not be the bulb end thats the problem... have you checked the wiring for resistance and breaks/shorts? Is there a short in the headlight assm?

    It might even be within the magneto access panel itself - something shorting within the engine ignition system that kills the engine when the light is switched on..

    hope that helped

    Jemma xx
  3. Gimmick

    Gimmick Guest

    well, i took the mag cover off, and could see anything obviously dubious, no wire wear, or bad connections, i do have a magneto in spare so i will try to replace the mag and see if the problem fixes...
  4. BSA

    BSA Guest

    Sounds like there is a hort circuit in the system or your magneto has got wet.

  5. Gimmick

    Gimmick Guest

    replaced magneto to no effect, tried different bike light same thing...as soon as the light lights up from the grounding of the fixture, boom, the engine dies...not a function of rpm either, does this over full rpm range, switching over to batt for now
  6. Gimmick

    Gimmick Guest

    ok, I am baffled. Now I am no electrician...but as i comprehend it, in order for a light to light up, the circuit must complete itself, so...when my white wire is hooked up to the light, the housing of the light grounds it to the frame of the bike, which makes the light light...so when the light is connected and a peddle the bike with the clutch out ( thereby turning the engine) my light lights, but...my bike will not start, in effect the light is acting like the kill switch does, grounding out the system, so why did it work before, but wont work now...
  7. BSA

    BSA Guest

    Keep the lights off until the engine is started and warmed up.

  8. fatboy67

    fatboy67 Member

    I might be wrong here, but if you have one of your other wires Blue or the black touching the frame OR if the wires are grouped together and they are shorted some where. When you turn your light on this will run back to the mag and short out the system. To my way of thinking thats all it could be. Some how the current produced by the white wire is making its way back to the mag.

    Hey how well does the light work?????
    Does it drain much power from the motor???
    Are you using a 7volt 3watt???
    Was thinking of either that OR a 12 volt battery system.
    Last edited: Aug 6, 2008
  9. Gimmick

    Gimmick Guest

    checked al the wires etc...no clue, light works OK, it is a 1950's Saf-t-Lite with a top switch and 2 bulbs, both 3 watt, out of a flashlight...if you are usaed to blackburn type lights it aint strong at all, but i mostly ride in the daytime so....