Hisun HS500ATV-2 Maintenance Manual page 27

Fix valve into guide,and look over the motion.
Inspection of valve spring
Measure the free height and squareness
Repairing limit value:(intake and exhaust) See figure
2-23-1, 2-23－2
free height of external spring: 43mm squareness: 0.8mm
free height of inner pring: 39.5mm squareness0.8mm
Figure 2-23-1，
6、Examining lifting distance of cam.
Measure the length of fillet with micrometer and check If
it is worn out
Repairing limit value:inlet lifting distance: 8.25mm
Exhaust lifting distance: 8.18mm.See figure 2-24.
Figure 2-23-2
27