How do you make a gokart faster?

on the carbeurator, there may be 3 screws, on mine, I twist the side one for air, bottom for gas , and another one above the 1st one, on a little spring on screwed on a little circle on it with a point on it, it is for ideling, twist it left, if it didnt work then, twist it to the right. ONLY twist it to make it go faster. twist the one for gas a TAD (little) bit. If that doesnt work, but on tall,narrow tires. I got 13.5 inch tires on the back of mine. my hub on my kart was a 4 hole hub. but the tires were 5 holed. so me and my papaw had to drill 4 holes for the bolts to go in. when you put the bolts on, 1st, put on a washer and a lock bolt then put them in. TRUST ME. ME AND MY PAPAW DID THIS, AND IT HELPED. I HOPE THIS WILL HELP YOU. :-)