First build - feeling the spark thru my frame!!

Discussion in '2-Stroke Engines' started by taureanirishman, Jul 17, 2009.

  1. taureanirishman

    taureanirishman New Member

    That's right, when my plug is attached and my CDI is hanging off my bike(not grounded), with the kill switch wire going nowhere at all and also not grounding out on the bike frame(coated it bed-liner btw)..

    So when the plug is attached to the motor and it's trying to start, my finger get's zapped if it touches the frame.
    Obviously I'm loosing spark power, but if my system is somehow zapping me thru the motor, doesn't that mean that my electrical system is conkers?!?!?!


    when I'm rolling down hill and pop the clutch I FEEL the electricity sparking in the handlebars!!! After going thru the newb checklist of things to look for:

    Fuel system is fine, no grit, everything moves freely, float isn't wet/cracked, when I pull the bowl drain screw and have the petcock open it dribbles freely.

    Clutch fully disengages and I can watch the piston move up and down(while getting my finger zapped on the handle bar)

    **Also, my CDI is ****, I was looking to remove the plug wire and it popped off, all there was at the end was a little metal nub that looks like it was supposed to push into a recess in the CDI box to make contact, no actual wires screwed into anything!!! Guessing this is the cheep version of the ignition, any suggestions of who sells quality ignition boxes(guessing SBP) would be appreciated

  2. arceeguy

    arceeguy Active Member

    Make sure the engine has a good electrical connection to the bicycle frame. I had used rubber to isolate and dampen vibration, but it electrically isolated the engine from the frame - producing the same "shocking" results you got when you popped the clutch!

    As far as the CDI goes, it seems that we are pretty much stuck with stock.

    I had adapted a Honda C90 12V CDI to work with the HT, but it involved rigging a trigger coil and providing the CDI with 12 Volts from a battery that needed to be recharged periodically. The system provided a much stronger spark, and engine performance improved a bit, but it was a lot of hassle. I haven't been able to get a Honda CRF50 magneto powered CDI to work with the HT's magneto. Not enough balls to drive the CDI I suppose.
  3. taureanirishman

    taureanirishman New Member

    No rubber used, could that be the problem?

    From what you posted I'm getting that the motor is SUPPOSED to ground to the bike frame??? That would reduce power to the spark(as is happening in this particular situation).

    Given the CDI box is not attached to the bike frame, the ground(white)wire is no where close to the frame... Would the fact that I haven't put the rubber strips between the motor and the bike be causing the grounding effect? Wouldn't the bolts and brackets that attach to the motor body cause the grounding effect also and continue to sap power from the system, thus keeping my HT from producing HT's?

    I'm just trying to make sure I understand how the electrical system on these things is supposed to work. But right now the fact that the motor is grounding out the ignition is making me think that the wiring is faulty in the motor itself???
  4. arceeguy

    arceeguy Active Member

    Yes - the engine should be connected to the frame. Technically, the black wire connects the ignition coil to the engine crankcase - but the pulses you are feeling are the voltage drop across that circuit. I recommend connecting a ground wire from the engine block to the frame with the black wire coming out of the engine. Then connect the black wire coming out of the CDI to the frame. The bike frame will complete the circuit and keep the frame at "ground potential" - just like a car or motorcycle.
  5. machiasmort

    machiasmort Active Member

    AG, Shoulda told him to get a metal seat! :idea:
  6. taureanirishman

    taureanirishman New Member


    didn't put the rubber in yet, but did split the black wires, scraped the paint off the frame in 2 places(about 2 inches apart) and attached using electrical tape(for the time being).

    Nothing different.... Going to try the greens next... between watching out for my 2.5yr old little princess anyway!!
  7. arceeguy

    arceeguy Active Member

    Hmmmm - Get a ohmmeter and make sure that th black wire has continuity to the engine crankcase. Maybe a defective stator coil?
  8. machiasmort

    machiasmort Active Member

    Thats what I'm starting to think too AG... Could he test that off of the wires with an ohms reading somehow?
  9. linnix13

    linnix13 Member

    mine always shocks me, i put electrical tape on the clutch lever, sometimes it will just shcok me out of no were and sometimes its fine, but il tell you the shock you get while traveling at 40kph is a killer!
  10. duivendyk

    duivendyk Guest

    Get Ohm meter,should have short to engine body on black wire,2.5 Ohm on white, and around 350 Ohm on blue.Get SOLID ground on frame,hose clamp will do, to connect engine ground to bare frame,so that ground return from plug is completed to the frame.Protect with paint or RTV.Use only ground return on CD unit to engine (blk to blk ),not separate frame grounds.Stay away from multiple frame grounds,often cannot be relied upon over time
  11. if anyone is getting shocked,then you have it hooked up wrong or somethings broken,like a wire maybe shorting to the frame.