A cadet kart with a 60cc motor (Swift, Rok) weighs around 140lbs, so at 115lbs. you guys will be a fair bit overweight. You can run without kart graphics and save a couple of pounds, but other than that not much you can do.
Most TAG Cadet classes run at 245. Most drivers run at 248-250 to be safe on weight. If you can get to 255 you can compete. With a 90 pound driver and 15 pounds of weight we ran at 248 or so.
You can hit ten pounds with some basic changes – 3.0 axle (assuming you are running a 5.0 like most current karts), mag front and rear hubs, mag sprocket carrier & engine mount, MXC or the new Swift wheels. Tillett T5 VTi seat is about as light as you can find. No graphics, no data in race trim, no heel stop (shouldn’t need it for a tall driver). May be able to order a kart unpainted. Fastech has a ton of titanium available if you really need an extra pound or two.
We have made some bigger kids pretty darn competitive – just takes some effort. Pick a good kart and make it light. Don’t pick a kart just for weight.
If you are running the stock axle Trent you’ll be able to save a bunch of weight right from the start there. The Intrepid has pretty nice vinyl graphics including the floor pan – can save about 2-3 pounds there as well. Are you running the stock cast aluminum wheels? A few of the magnesium wheels will offer a pound plus in savings.
What races around Texas will you be running? My daughter runs cadet at our club (HCKC) and in the Texas Sprint Race Series. It’s a 245 lb min weight for that class in those races, which I believe is also SKUSA’s min for that class. We typically come in anywhere from 247-252 in weight after each race. Race ready, our kart weighs around 160 lbs. right now with 10 lbs of ballast added. We’ve raced with a few kids that have no problem making weight, and have no weight added to their kart, so you’re not alone.