2006 Arctic Cat Y-6/Y-12 50cc and 90cc Service Manual, Page 39Get this manual
Removing Valves NOTE: Keep all valves and valve components as setNote the original location of each valve set for use during installationReturn each valve set to its original location during installation
MEASURING VALVE STEM TO VALVE GUIDE CLEARANCE
1Using valve spring compressor, compress the valve springs and remove the valve cottersAccount for an upper spring retainer
1Insert snap gauge 12 way down into each vlave guide bore; then remove the gauge and measure it with micrometerRecord the measurement2Using micrometer, measure the outside diameter of the valve stem near the middleSubtract this measurement from the valve guide bore to obtain the clearance measurementClearance must not exceed specificationsMEASURING CYLINDER HEAD DISTORTION
1Lay straightedge across the cylinder head; then using thickness gauge, check the distortion between the head and the straightedge
2Remove the valve seal and the lower remaining spring seatDiscard the valve seal
2Maximum distortion must be within specificationsCLEANINGINSPECTING CYLINDER