There are so many competing interests in kart racing. Importers and business owners vying for diminishing dollars. You’ll get a ton of advice and some of it will be useful. It does seem like promotors and series sponsors are starting to get the message that we need to focus our sport a little better so it’s easier for new people to figure out and for veterans to stay happy and solvent.
In 3 years we’ve tried Yamaha, PRD, HPV and now X30. Always chasing bigger classes and reliable, fast engines. As David says you need to see what class excites you where you’re going to race and equip yourself to run it. After that you just have to hope that the class stays fun, competitive and relevant. If it doesn’t, you end up running 4 different types of engines in 3 years.
At the end of the day you may be frustrated and broke but you’ll be hooked and counting the seconds until you get back to the track.