So I just bought two Harbor Freight Predator 212cc engines, one for a mini bike and another for a go kart. I am planning on performing several mods, such as governor removal, air filter and header upgrade, etc. I just wanted to know, after removing the governor, since the engine isn't optimized for higher rpms, what should I upgrade to improve life span? I heard that it is good to change the valve springs and billet flywheels but I would like more information on that.