I agree with Andy. Junior should be the class that kids race in if they are of school age, basically under 18, Cadet should be until you are around 13. That would allow kids to learn and actually get good at one class before they move up. Lower the weights in Junior and lower the horsepower, karts will go the same speed but last way longer. Currently the weight in senior is crazy. If the average of the racers are carrying 30+lbs then lower the weight at lease half that amount.