It is important to remember that all karts need to have a wheel alignment done prior to each new day on the track.
The first stage to doing a front wheel alignment is making sure you have set the height of your chassis steering wheel to where you find it will be most comfortable for your driving style. On Top Kart chassis, the plastic steering shaft support is adjustable with 2 holes as well as with the ability on the chassis uprights 2 different positions to mount the steering shaft support based on your preference.
Once your steering wheel position is set, make sure that your steering spade at the bottom of the steering shaft (where the tie rods are mounted to) is completely vertical position. You may use a small bubble level to help set this to be accurately straight. Also to keep this from moving, you may also use vice grips and gently lock the steering shaft in place by clamping onto the plastic steering shaft support.