Weird spark issue.
 

I purchased a used off road go kart the other day. The engine is a 150cc GY6. I recently purchased a new rectifier, cdi, and electric choke for it. I installed those items and all is good. I started the engine this morning and noticed something weird. The engine starts and runs, how ever i noticed that while it is running, the rear chain has sparks jumping between the links. Only place i notice sparks. I checked ask the connections i could find and they all look fine. Made site the spark plug boot was on tight. I am kind of stumped. Any ideas would be great

Check all the grounds ( green wires and black wires)

Yeah something is grounding out. You have a wiring rubbing somewhere.

wouldn't it be a power wire touching somewhere and not a ground?

yeah, a hot wire hitting metal which is grounding the connection out..and with the chain contacting when rotating is causing the spark to form from the metal on metal contact

and now i know, which is apparently half the battle lol

No. If a ground is detached, it would cause that circuit to find a path for ground, which could cause that hot on the circuit to find a ground if it touched any grounded metal.

Case and point, if a neg (cold) wire is too corroded on a car, the pos (hot)side can and will cause all kinds of melting. This is the #1 way fuse blocks and severe electrical fires happen in cars.