I know it's an old thread that i'm replying to, but I've dealt first hand with people ruining the box stock predator class. I was raised to follow the rules in life and I carried that along with racing. If a track is going to run a BOX STOCK predator class, keep it as BOX STOCK. When these race promoters decide it's a great idea to allow removing the governor, or add a weenie pipe, or "stage 1" kit, billet flywheel, fuel pump, valve springs etc. You, as the race promoter, have failed all of us regarding the box stock predator class. Why allow anything other than what the class is called, BOX STOCK? I've been involved with racing for nearly 25 years, came from a motocross racing background and decided to get my son and I a kart to run this BOX STOCK class as it was an affordable way to race without the risk level on 2 wheels. It was supposed to be a class with everyone running the same engine, which was supposed to be the skill of driver/setup vs. money and motor, right? After this first year of racing karts, it will most likely be the last. Race promoters need to stop catering to certain individuals. A BOX STOCK class should be just that, BOX STOCK. It's a $99 engine, when it fails they can go buy another. Leave the governor, air box, exhaust, valve springs and flywheel BOX STOCK. As a race promoter or a tech at the track, you may lose some friends, but the integrity of the BOX STOCK class is far more important than little Johnny and his dad being angry after they get DQ for not following the rules.