If you have a wide variety of karting equipment in your area, and you are willing to risk being different, you could set up classes based upon lap times rather than by engine and weight class. You qualify all your karts, then group them into classes based upon similar qualifying times.
Some might sandbag during qualifying in order to gain an advantage in the races. You can combat this by having your best payouts in the fastest classes, and by timing leaders during races. You’ll need to decide how much speed gain is acceptable throughout the night, and black flag karts that exceed that – they are moved to start at the tail of the next fastest class (class order is from slowest to fastest).
Advantages: every safe kart that shows can race, no engine protests or tech or weighing or fuel tests, and generally low budget or low experience teams don’t end up having to race against the hot dogs (which helps encourage them to come back).
Drawbacks: the anti-sandbagging efforts, teams can’t enter multiple drivers using the same kart in different weight classes, and you could still end up with a lot of specialized classes due to kid class rules (different restrictor plates and ages), cannot run kids with adults, and because you can’t run flat karts and caged karts together.
In the end you will probably have to cater to the most popular engine / chassis / weight classes in your area, and use the same class structure and rules that other tracks in your area use. But lap time classes might create your own niche and draw teams that don’t fit into what those other tracks are doing.
