Yes, by changing the “Cam” a valve can be made to skip over outlets to change the number of active outlets /zones. The Cam is a small circular piece held in place by 2 screws on top the 4000 and inside the top of the 6000 valves.
4 outlet 4000 series indexing valves can be Cammed for 2, 3, and 4 zones, 6 outlet 4000 valves can be Cammed for 2, 3, 4, 5 or 6 zones.
4 outlet 6000 series indexing valves can be Cammed for 2, 3 or 4 zones however the 6 outlet 6000 valve can only be Cammed for 5 or 6 zones.