Adds about 1-2hp and amplified torque more than stock carb and it is gas combination adjustable. The 22mm is the appropriate option if you are jogging stock valves Join our mailing list and be the first to get many of the latest updates, sales news and presents from GoKarts USA https://bike-engine-guard49378.ssnblog.com/34092719/5-simple-statements-about-are-lift-chairs-worth-it-explained