Since you should only use the safety washer four times before replacement, it is wise to keep a small supply of spare safety washers. These washers only cost $0.88 apiece. I need to remember to order some of these safety washers the next time I get parts from CSC.
The CSC part number for these safety washers is Z20-113.
The Suzuki DRZ400S/DRZ400E motorcycles also use a counter shaft with very similar, or identical dimensions. These bikes also use a 30mm nut to secure the C/S sprocket to the counter shaft.
Therefore, if you are in a pinch, you can also use the Suzuki safety washer designed for these motorcycles. The safety washer has Suzuki part #09167-22012.
The Suzuki safety washer is held in place by the splines of the counter shaft.
After placing the 30mm nut over the washer, bend part of the washer over one side of the nut with a pair of pliers.
__________________
Spud
"Never argue with an idiot. He will drag you down to his level, and beat you with experience."
Mark Twain
2015 Zongshen ZS250GY-3 (RX3)
2006 Zongshen ZS200GY-2 (Sierra 200)
2005 Honda XR650L
2004 Honda CRF250X
1998 Kawasaki KDX220
Mods made to my Zongshen ZS200GY-2:
http://www.chinariders.net/showthread.php?t=6894