HOW CAN i IMPROVE MY GO KARTS PREFORMANCE?

IT HAS A 5.5 HORSE POWER ENGINE. WHAT DO I DO TO MAKE IT FASTER ETC? PLEASE HELP ME!!!!!!!|||re gear it, larger on front, smaller on rear will make it go faster,opposite will make it slower with more power|||Take the engine out and install a V8.|||use a better spark plug and change the oil more often