im not totally sure of the sprockets, but i know there are some avaiable. dennis kirk or JC whitney would be the place to get them. i know they had a selection for my DT1. i did some research for you and found out right now they have a 16 and 37 combo set that yoi can get. im not sure what stock is, but thats a start. i aslo have a question for you. i have a 79 xs400 and i cant get it to idle very good. i have had the carbs apart, and they should be good. it will idle for a bit, then drop a cylinder, and quit. i was wondering what year your bike was, and how does it run? thanks for your help. if you coudl email me back at Tommg21@juno.com, that would be great. thanks a lot for you help!!!