One way to put the great observations of @tankyx, @tjkoyen & @Richard_Jacques into the overall cornering context is to think about each turn from the desired exit (location, trajectory, speed, and acceleration rate), to the rotation point (typically at or near the apex), back to the braking and entry point. That is, to create the exit you desire, you must manage the entry so that you can rotate the kart in balance with the kart/setup/track combination.
To produce balanced rotation at the correct location, you must manage the amount of work the outside front tire is doing (by managing the load that the speed you are carrying generates) so that the energy/speed creating the load peaks at the rotation point, and the trajectory taken into the apex produces the desired amount and rate of yaw. Doing this correctly means you arrive at the rotation point with no more, and no less, than optimum speed.
If you arrive at the rotation point with too much speed, you will alter your desired trajectory to the outside of your desired line (because excess energy will still be causing large slip angles for the front tire), which can cause you to go wide of the apex and slightly delay rotation. This means you have to slow down more that optimal to get the kart to rotate enough to try and get back on your line. Drivers often respond to this mistake by snapping the gas on ASAP after the kart starts rotating, because they are trying to make up for speed they lost by running wide and by having to wait for the yaw rotation to take effect. However, depending on the timing relative to rotation rate, snapping the gas on can either induce a large understeer or a snap oversteer; both of which typically require a lift and are not good for lap times. If you make this mistake it’s best to take the smaller penalty of waiting for the kart to rotate, and rolling on the gas as smoothly as possible.
If you arrive at the rotation point with insufficient speed, then the trajectory (slip angle) of your front end will be collapsing in towards the apex because there is insufficient energy to maintain the tire load/slip angle. If this happens then yaw rotation starts, early, but with insufficient energy to get the kart all the way rotated for the exit of the turn. This often looks like parking/turning the kart at the apex, and then driving a kind of straight line from the apex out to the exit point of the turn (so driving a line out of the turn instead of drifting the kart out on the optimal line/trajectory). The driver response is often the same as for carrying in too much speed (i.e. whack the throttle open).
When you get this speed at the rotation point right, it’s a beautiful thing because the kart just rotates smoothy, predictably and effortlessly. However, managing the rotation (the transfer of load from the outside front tire to the outside rear tire), requires great precision in both throttle and steering inputs. One way to think of this is to consider it like the opposite of trail braking. In trail braking you decrease braking pressure concurrently and proportionally to increasing steering input, in order to manage the load on the outside front tire when braking into a turn. When you get on the gas to manage rotation, you should decrease steering input concurrently and proportionately to increasing throttle). Many drivers seem to treat throttle and steering as separate things, but doing so creates a situation where your steering is behind (reacting to) your throttle input, instead of them working together to create a balanced application of load to the outside rear tire. An imbalance in throttle/steering can often set off oscillations of energy during acceleration that can require multiple steering and/or throttle corrections to manage.
Try to feel what the power does to the load and grip. Play around with that.
