Possible magneto or CDI trouble, help please

Discussion in 'Electrical' started by Teklor, Aug 5, 2015.

  1. Teklor

    Teklor New Member

    Good evening folks,

    So the other day i had my 66cc grubee skyhawk out for a drive. It started bogging badly after about 15 minutes of driving. I couldn't get it past about half throttle without it bogging and the engine sputtering. I turned around to come home and made it about 2 minutes down the road and it died. I checked everything over and found i couldn't get a spark to the plug. I have 2 plugs here that came with the kit and both produced the same results. I borrowed an ohm tester from a friend and get a reading of 340 from the coil but i can't get any type of reading from the CDI. I tried every possible wire color combination and nothing happens on the meter. Does this mean my cdi is shot? or am i doing something wrong?

    Also, when i removed the magneto/coil, I noticed a tiny bit of oil on the end of one of the bolts, the coil assembly looked like it might have had a little oil on it, but nothing crazy. I know this is a sign of a crank gasket going but i'm wondering if this might have had something to do with my issue now.

    Thanks for your time

  2. crassius

    crassius Well-Known Member

    sounds like a bad CDI - oil on the bolt may be because the case was drilled all the way thru into the crank area as I've sometimes seen happen - this is OK as long as that bolt is kept tight

    oil around the seal under the rotor is bad tho
  3. Teklor

    Teklor New Member

    I'll order a new cdi and cross my fingers. Is there an easy way to check the seal to make sure that it's nothing major? I've had the magneto bolts out for 2 days now and there's no oil seeping out or anything. I'm fairly mechanically inclined but my experience is with cars....and I've never changed or inspected a crank shaft before.
  4. crassius

    crassius Well-Known Member

    just a visual inspection after rotor is removed will let you see if it's dry there, but I'd doubt there is a bad seal until I'd checked the ignition