6. CYLINDER HEAD/VALVES STRYKER 125/150 SERVICE INFORMATION GENERAL INSTRUCTIONS · The cylinder head, cylinder and piston can be serviced with the engine installed in the frame. · Before disassembly, clean the engine to prevent dust from entering the engine. · When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts, valve arm and camshaft sliding surfaces for initial lubrication. · The valve rocker arm is lubricated with engine oil through the cylinder head engine oil passages. Clean and unclog the oil passages before cylinder head assembly. · Remove all gasket material from the mating surfaces. · Do not use a driver to pry between the cylinder and cylinder head, cylinder and crankcase. · Do not damage the cylinder inside and the piston surface. · After disassembly, clean the removed parts before inspection. When assembling, apply the specified engine oil to movable parts. SPECIFICATIONS Standard (mm) Service Limit (mm) Item DA25AA DA30AA DA25AA DA30AA IN 0.08 0.08 Valve clearance (cold) EX 0.08 0.08 Cylinder head compression pressure 13 kg/cm 16 kg/cm Cylinder head warpage IN 31.80 31.80 31.40 31.40 Camshaft cam height EX 31.54 31.54 31.140 31.140 IN 12.0~12.018 12.0~12.018 12.10 12.10 Valve rocker arm I.D. EX 12.0~12.018 12.0~12.018 12.10 12.10 Valve rocker arm shaft IN 11.977~11.995 11.977~11.995 11.910 11.910 O.D. EX 11.977~11.995 11.977~11.995 11.910 11.910 IN 1.0 1.0 1.80 1.80 Valve seat width EX 1.0 1.0 1.80 1.80 IN 5.450~5.465 5.450~5.465 5.370 5.370 Valve stem O.D. EX 5.430~5.445 5.430~5.445 5.370 5.370 IN 5.475~5.485 5.475~5.485 5.780 5.780 Valve guide I.D. EX 5.475~5.485 5.475~5.485 5.780 5.780 Valve stem-to-guide IN 0.010~0.035 0.010~0.035 0.080 0.080 clearance EX 0.040~0.055 0.040~0.055 0.10 0.10 6-2