The factory normally sets them up with tow on the throttle and one on the chocke linkage, but there are many ways to skin this cat, so you don't have to copy the factory and I normally do not. The choke lever arms is already sprung on the side lever, but all factory applications still put atleast one return spring on the choke linkage bar, old racer's trick to use two to always insure the jet can't drop duirng high rpm, where vibration is at the most, it can and does happen. I normally use two on the throttle linkage, one at each throttle linkage lever arm (none in the center), since the throttle has no spring in the side lever like the choke, I prefer two, kinda like a safety back up system.