About finished up this old Honda C110 (original 50cc with 4 speed manual trans, pushrod style/points) and encountered a common issue with the throttle not returning very quickly. It uses a internal pull that engages a "rifled" throttle tube. The spring in the carb is all that returns it. Has new throttle cable, and everything's lubed well. So far, finding a replacement spring that fits, with more tension has been futile. I thought about adding a spacer for weight and to preload the spring on top of the barrel/slide...Any other ideas?