Does anyone know or has anyone ever replace/upgraded the valve springs in a predator 79cc engine. Also what about the valves, what size valves are in this engine and can you get heavier valve springs , retainers and SS valves for this engine. Looking to try to do some mods. on one of these engines so i can keep the rpm's up. Don't want to float valves at a high rpm. Surely someone has tried to build one of these. New project.