2006 Arctic Cat DVX 400 Service Manual, Page 14Get this manual
4Install the selected shim at the valve stem with the numbers facing the tappetBe sure to measure the shim with micrometer to ensure it is the proper sizeRefer to the tappet shim selection table for detailsNOTE: Apply molybdenum oil solution to the top and bottom of the tappet shimMake sure that the numbered side is directed toward the tappet 5Install the camshaft (see Section 3)ATV2151
NOTE: These numbers indicate the thickness of the tappet shim as illustrated