Welcome Kymco Owners!
Negative lead ran directly from the battery to the engine casing to be grounded. The last mechanic must have done this without zip ties to run the cable neatly. Ground wire touched the exhaust header and melted away. I saw another GTI and decided to check out the wiring, and the ground wire ran from battery-frame (next to the coil) and then to the engine casing. So this means that it wasn't properly grounded which explains the electrical issues and decline in performance.