84 RM has no spark

Joined
Sep 11, 2003
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#1
My RM has no spark and i can't figure out why. There are 3 wires coming from the stator going to the CDI box, which i can't fiure out what the 3rd is for. My stator has 2 coils on it. The only wire from the top one connects to a contact on the bottom coil. This wire has voltage, meaning that it would be the + wire. The 2nd wire is the ground. The other wire comes from the bottom coil and has no voltage, and i have no idea what it is. There is no voltage going to the coil. All connections are good. Is the CDI box bad? The bottom coil on the stator? Any other suggestions? Does anyone know where i could find a wiring diagram?

Thanks in advance,
Shawn
 
Joined
Oct 10, 2003
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#2
One coil is the "charge" coil, it generates about 200 volts to power the CDI. The other coil (smaller) is the "trigger" coil that tells the CDI when to fire. They use a common ground ground wire. You should be able to set your volt meter on the AC volts setting and measure voltage produced as you kick it over. The trigger coil probably only puts out 10 to 30 volts AC, and the charge possible less than 150 during kick over. Your manual may give resistance reading for these. If they are both producing voltage, your problem could be a bad CDI, spark coil or wiring. You might also have a bad (open) plug wire too.