There are 5 potential things that could be wrong here. Bad key switch, bad kill switch, bad extension harness, bad powerpack or bad stator.
Disconnecting the round plug will separate the stator and powerpack from the rest of it. If spark comes back when disconnecting, the problem is a bad keyswitch, kill switch, or harness.
If there is still no spark, either the powerpack or stator is bad. The powerpack is not testable but the stator is. Disconnect the stator from the powerpack and measure the resistance between the brown to brown/yellow wire. It should read 450 to 550 ohms. If not, replace the stator. If yes, replace the powerpack.
Does that all make sense?
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