To modify the maximum speed on a Yamaha gas cart requires no tools, no retro fitting, a ty-wrap applied in the right spot will make your cart go from 20mph to 25.5 mph. To remove it, takes one second with a knife.
BTW, the biggest mistake by new golf cart drivers in the area south of 466A. Are drivers going east on Pinellas and when they reach Morse, rather than turn left and go through the tunnel, they stay on Pinellas and go around the traffic circle in front of the fire station. One of the busiest and most dangerous traffic circles in TV. I've witnessed it a couple of times. Have to get to the Sarasota Driving Range or Walmart, can't take time for the tunnel.