Caster, Positive stablelises rearward thrust from forward motion , Look at the front caster wheels on a shoping cart, or look at the rake on a bicyle.
Adj - For LTO , If the RF has more POS+ castor than the LF the kart will pull left, Reason is because the more caster angle on the right can resist the rearward force,The force is trying to push the Rf back,But due to the king pin angle liening back pressing the tire in to the ground. This is called caster split, A offset kart can pull left with even castor, say +10&10
The less caster the more turning power, The less jacking efect, Driver strenth, input, feel, track condition are some of factors when FINE tuneng with castor.
Shims, washers, tires, any thing that efects the hight of one spindle will change its weight and the other three, LTO the RF/LR is refered to as cross or wedge.
a taller LR RF or a smaller LF RR tire , more shims under LF more over RF would = more cross.
Thats as simple as it gets and were simple stops. Donn