EG–52 ENGINE – ENGINE MECHANICAL 3. INSPECT CYLINDER HEAD A. Inspect for flatness Using precision straight edge and feeler gauge, measure the surfaces contacting the cylinder block, intake and exhaust manifolds for warpage. Maximum warpage: 0.10 mm (0.0039 in.) If warpage is greater than maximum, replace the cylinder head. P02271 P13184 209528 B. Inspect for cracks Using a dye penetrant, check the combustion chamber, in- take ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head. P02136 4. CLEAN VALVES (a) Using a gasket scraper, chip off any carbon from the valve head. (b) Using a wire brush, throughly clean the valve. EN0580 5. INSPECT VALVE STEMS AND GUIDE BUSHINGS (a) Using a caliper gauge, measure the inside diameter of the guide bushing. Bushing inside diameter: 6.010–6.030 mm (0.2366–0.2374 in.) EM7717 P02073 202413