Thanks Robert. I am new to the kart scene and have a lot to learn about jetting and gearing. I am a little in the heavier side at 200 lbs and Ann in a CIK chassis. Thank you for your advise I will use the 19-22 as a starting spot. Any tire recommendations? I was not able to find if WKA mandates a specific tire for stock honda 125 shifter. But if it is open, what do you suggest?