North Texas Karters

Here's a link to the exhaust that's legal.

http://www.arcracing.com/servlet/the-45 ... ARC/Detail" onclick="window.open(this.href);return false;

I think most people try to get close to a 4:1 ratio. So 15t from the motor and 60t axle sprocket as an example. Everyone is different especially depending on which class you're in but it's fairly close to this. If you want more rpm's then going up in tooth count on the axle sprocket will help. A big...