If you google to affordable go karts they have many parts. I recommend disconnecting your gov. or adding some more springs to the gov arm untill it lets it rev to about 5000 RPM. By adding more springs you are assured That you dont rev it too high and brake something. When you rev it that high I would recommend a billet rod from arc. After that there are endless things you can do with a clone. Just exhaust and intake can easily get you 7hp. As far as sprocket set ups. Id buy a 30 series torque converter and get a 9t engine sprocket and 60t axle. You will have really good acceleration for off road and decent top end.