Hey, cool to see some newbies in karting. GoPro Motorplex is an amazing facility.
Unfortunately, the methanol engine, I imagine a methanol Briggs & Stratton Animal, is only in use in select tracks around the northeast and midwest, and is currently being phased out by WKA’s Gold Cup Series by a gasoline version that is meant to be longer-lasting between rebuilds, and more reliable. Either way, neither of the engine versions are currently used at your local track, GoPro Motorplex. Your only option for your son at GoPro will be to run in the Rotax Micromax division, which begins at age 7, so he could practice until he becomes old enough. Also, since you are new to the sport, I recommend buying a chassis brand from a dealer near GoPro, such as KartSport North America, a national team with a shop located at the track. They deal in OTK (FA, a version of TonyKart, Kosmic, and Exprit) and Arrow chassis, and have nearly anything and everything karting-wise that you will need at their on-site shop. While you currently have some chassis of your own, if there is not a dealer near, or someone with the same brand that you have a good relationship with, karting may be a bit tough to start out in. You would have the option to run in Yamaha Senior, TaG Senior, Briggs & Stratton LO206 Senior (a slower engine of the same brand as the methanol engine you purchased), or Rotax Senior.
Budget-wise, it can vary due to the amount of races you want to do, etc. Let me first begin by wanting to go all the way to the pros will cost you hundreds of thousands of dollars, maybe even a million or two. In Karting, most teams charge anywhere from $400-$1500 per weekend to be underneath their “tent”, with assistance, coaching, setup advice, and any parts that need to be purchased and installed available on their haulers. If you go with a mechanic/tuner, they can cost anywhere from $600-$1500 per weekend, depending on who you go with. Top drivers will get both a tuner and a team for each national weekend, which can total up, and we haven’t even gotten to the race yet.
A brand new kart chassis, (all but motor mount and motor package), will run for $4600-$4900 new, and your engine packages can range from $1000-$3500, depending on which engine class you race in, and if you get it new or used. You will also want to make sure that the engine builder you choose to buy an engine from attends all of the national events that you want to race at, so you can get their support if something is a miss with your motor.
Outside of trackside support, you have numerous other expenses for a national weekend. First you have your sets of new tires, which depending on which event you go to, can be as many as four new sets for one class, or as little as one new set for racedays for one class. One new set of tires will go for roughly $225, and one set of wheels for anywhere from $180-$250. You won’t need to get a new set of wheels for every set of tires, but you need a couple sets of wheels to change out tires on and have a set to have rains mounted on. Entry fees are usually $250-$400 depending on the series, and then your hotel bills will usually be for three to five nights each, ranging from as low as $200 to as high as $500 for the amount of days, depending on the class of hotel.
Overall, you’ll be spending a lot to run national events in karting, along with test days to stay fresh in between. Top drivers spend between $30,000 and $90,000 each year, with some spending more than six digits to attend as many national events as possible.