6. CYLINDER HEAD/VALVES STRYKER 125/150 Valve Areas INSPECTION CYLINDER HEAD Check the spark plug hole and valve areas for cracks. Check the cylinder head for warpage with a straight edge and feeler gauge. Service Limit: 0.1mm repair or replace if over Spark Plug VALVE SPRING FREE LENGTH Measure the free length of the inner and outer valve springs. Service Limits: Inner spring : 39.4mm Outer spring : 46.2mm Outer Spring Inner Spring VALVE /VALVE GUIDE Inspect each valve for bending, burning, scratches or abnormal stem wear. Check valve movement in the guide. Measure each valve stem O.D. Service Limits: IN 5.37mm replace if below EX 5.37mm replace if below 6-9