7. CYLINDER HEAD/VALVES PEOPLE 125/150 Remove carbon deposits from the combustion chamber. Clean off any gasket remnants from the cylinder head contact surface. Be careful not to damage the cylinder head mating surface. INSPECTION CYLINDER HEAD Check the spark plug hole and valve hole areas for cracks. Check the cylinder head for warpage with a straight edge and feeler gauge. Service Limit: 0.05mm repair or replace if over VALVE SPRING FREE LENGTH Measure the free length of the inner and outer valve springs. Service Limits: Inner : 31.2mm replace if below Outer : 34.1mm replace if below VALVE /VALVE GUIDE Inspect each valve for bending, burning, or abnormal stem wear. Check valve movement in the guide. Measure each valve stem O.D. Service Limits: IN : 4.90mm replace if below EX: 4.90mm replace if below 7-9