Read, try, read, try… is the best method for kart tuning.
The difficult part of kart tuning is that one adjustment can cause two completely different handling characteristics depending on track conditions, class, chassis, driving style and all the other outside influences.
The best thing you can do is test and learn exactly what certain handling imbalances feel like and what it feels like when adjustments are made. It seems obvious, but you need to know what the kart is REALLY doing to be able to adjust it. People say “it’s loose” or “it’s tight” but it needs to be broken down further. Is it “tight” because the inside rear isn’t lifting? Or is it “tight” because the inside rear is lifting too much and slamming back down right away? Opposite issues that can feel the same if you don’t know the difference. You might end up going in the complete opposite direction you need to to fix the problem. This is why breaking the corner down into entry, apex, and exit is so helpful. It helps you figure out what the kart is doing in chronological order of when it happens in the corner. If you go into a corner and feel the kart sliding out at apex, you’d say the kart is oversteering. Well if we look at the entry of the corner, maybe your kart feels twitchy. Now we can diagnose that the twitchiness is causing the sliding and we know that we obviously need to narrow the front a bit to get some front grip out.
Karting adjustments are always conditional. Meaning there isn’t a standard or set effect you’ll get from an adjustment every time.