inside your kill switch wire you have two wires - black wire to ground and the other to connect into the blue wire from the motor! as far as the chain coming off - do you have your tensioner on correctly and adjusted right ? and how about your rear sprocket that you added , is it true and straight ?

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" We cannot live through a single day without making an impact on the world around us. And we all have free choice - what sort of difference do we want to make?" ~Jane Goodall~