8. CYLINDER HEAD/VALVES UXV 500 SERVICE INFORMATION GENERAL INSTRUCTIONS · The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator and water jacket must be drained first. · When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts and valve arm sliding surfaces for initial lubrication. · The valve rocker arms are lubricated by engine oil through the cylinder head engine oil passages. Clean and unclog the oil passages before assembling the cylinder head. · After disassembly, clean the removed parts and dry them with compressed air before inspection. · After removal, mark and arrange the removed parts in order. When assembling, install them in the reverse order of removal. SPECIFICATIONS Unit: mm (in) Item Standard Service Limit IN 0.1 mm (0.004 in) Valve clearance (cold) EX 0.1 mm (0.004 in) Cylinder head compression pressure 15 kg/cm2 (1500 kPa, 213 psi) Cylinder head warpage 0.05 (0.002) Camshaft runout 0.05 (0.002) IN 37.2614 (1.4905) 37.11 (1.4844) Camshaft cam height EX 37.0084 (1.4803) 36.86 (1.4744) IN 10 (0.4)10.015 (0.4006) 10.1 (0.404) Valve rocker arm I.D. EX 10 (0.4)10.015 (0.4006) 10.1 (0.404) Valve rocker arm shaft IN 9.975 (0.399)9.99 (0.3996) 9.9 (0.396) O.D. EX 9.975 (0.399)9.99 (0.3996) 9.9 (0.396) Rocker arm to shaft clearance 0.009 (0.0004)0.042 (0.0017) 0.1 (0.004) IN 4.975 (0.199)4.99 (0.1996) 4.925 (0.197) Valve stem O.D. EX 4.955 (0.1982)4.97 (0.1988) 4.915 (0.1966) IN 5 (0.2)5.015 (0.2006) 5.03 (0.2012) Valve guide I.D. EX 5 (0.2)5.015 (0.2006) 5.03 (0.2012) Valve stem-to-guide IN 0.01 (0.004)0.037 (0.0015) 0.08 (0.0032) clearance EX 0.03 (0.0012)0.057 (0.0023) 0.1 (0.004) 8-2