Not getting any spark

Fletch

New Member
Aug 8, 2018
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I'm using the new "BT80" electric start motor. My CDI stopped giving me spark, but one off an old China girl motor would give me a spark, only I couldn't run my bike with it. I assumed I needed a new CDI, so I got the one that comes with this style motor, and still I get no spark from the CDI. Only getting a spark from the China Girl CDI. Could I have bought a faulty CDI? I am stumped.
 

Greg58

Well-Known Member
May 1, 2011
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Newnan,Georgia U.S.A.
You could have a bad magneto coil, they sometimes get wet if you've ridden in the rain because the grommet in the case doesn't seal good sometimes.
 

Fletch

New Member
Aug 8, 2018
12
2
3
26
I am not finding much information about CDIs on this new motor, so I got to the generator coil inside the motor to follow the wires and find out why there were 3 wires to the CDI, when I was able to get spark with just 2 wires on a China girl CDI.
It appears that there is a power/ground, while the 3rd wire is to a timing sensor. This makes sense now, the 2 wire CDI changes its timing as it gets more power from the magneto, so just giving it power caused it to create a spark. The 3 wire CDI gets a signal from a sensor. I believe this is where my problem lies. I'll replace the generator coil which comes with the sensor and hopefully that gets it running.
 

Fletch

New Member
Aug 8, 2018
12
2
3
26
I have replaced both the CDI and magneto coil and still no spark...I have tried 2 different spark plugs that I know both work. I'm completely at a loss of ideas.
 

Greg58

Well-Known Member
May 1, 2011
4,140
1,032
113
62
Newnan,Georgia U.S.A.
Try removing the kill switch from the circuit, a kill switch should have two wires to it unplugging one will break the circuit. I assume you have removed the sparkplug and held it on top of the head to check for fire, the electric start will make it easy.