2006 Arctic Cat Y-6/Y-12 50cc and 90cc Service Manual, Page 10Get this manual
3Remove the spark plug wire and the spark plug; then rotate the engine clockwise to the TDC position on the compression strokeNOTE: The "T" mark on the rotorflywheel is aligned with the timing pointer on the crankcase, and intake and exhaust valve adjuster screws must not have pressure on themThe two punch marks on the camshaft gear are aligned with the valve cover surface, and the hole in the timing gear points away from the engineCD659 CD652 CD658
5Check the valvetappet clearance after the jam nut has been tightened to ensure that the clearance did not change
4Using feeler gauge, check each valve tappet clearanceIf the clearance is not within specifications, loosen the jam nut and rotate the tappet adjuster screw until the clearance is within specificationsTighten each jam nut securely after completing the adjustmentVALVETAPPET CLEARANCE