Here's another tip.
When the bike is new, the marks on the cam sprocket ('L' and 'R'), should align very well with the marks on the cam inspection ports when the TDC mark on the flywheel aligns with the inspection hole of the stator cover.
As you ride more miles the cam timing chain will gradually elongate. When the marks on the cam sprocket no longer align very well with the marks on the cam inspection ports, it is time to replace the cam chain.
__________________
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