In the interest of helping other riders, I have compiled the following information regarding the availability of countershaft sprockets for these Yamaha and Zongshen motorcycles. To the best of my knowledge, countershaft sprockets for the two bikes are available from seven different manufacturers. If I have made any errors, or omitted any important information, please do correct me.
PBI is a company located in Oregon. They manufacture the following countershaft sprockets that will fit the TW200/Sierra 200GY-2:
12-tooth sprocket, part #50-733-12
13-tooth sprocket, part #50-733-13
14-tooth sprocket, part #50-733-14
15-tooth sprocket, part #50-733-15
I have also seen reports of a 16-tooth sprocket, part #50-733-16. However, this sprocket might not be currently manufactured.
All PBI sprockets should be able to use the Zongshen/Yamaha sprocket bolts and retaining clip without modification.
Parts Unlimited also markets countershaft sprockets that fit the Zongshen 200GY-2:
13-tooth sprocket, part #K22-2601B
14-tooth sprocket, part # K22-2675
15-tooth sprocket, part # K22-2601C
It has been reported that the Parts Unlimited sprockets require larger bolts, and larger holes must be drilled in the sprocket retaining clip.
JT Sprockets produces one model that fits the TW200/Sierra 200GY-2:
14-tooth sprocket, part #JTF 1559.14
Sprocket Specialists produces two models that fit the Zong 200GY-2/Yamaha TW200:
14-tooth sprocket, part #566-14
15-tooth sprocket, part #566-15
It has been reported that these sprockets are a very tight fit on the countershaft.
Sunstar Sprockets makes one model that fits both dual sport motorcycles:
14-tooth sprocket, part #21314
Of course, Yamaha markets a sprocket for their TW200:
14-tooth sprocket, part #93823-14149-00
And finally, Zongshen manufactures a sprocket for its Sierra 200GY-2:
14-tooth sprocket, part #23401-L067
Spud
