2011 Arctic Cat 400 TRV ATV Service Manual, Page 38Get this manual
5Match the width of the plasti-gauge with the chart found on the plasti-gauge packaging to determine camshaft to cylinder head and valve cover clearance
NOTE: With the weight extended, the unloader pin should be flat-side out; with the weight retracted, the unloader pin should be round-side out
6If clearance is excessive, measure the journals of the camshaft