CYLINDER HEAD/VALVE SERVICE INFORMATION 10-1 VALVE GUIDE REPLACEMENT 10-13 TROUBLESHOOTING 10-2 VALVE SEAT INSPECTION/ REFACING 10-14 CAMSHAFT REMOVAL 10-3 CYLINDER HEAD ASSEMBLY 10-15 CYLINDER HEAD REMOVAL 10-7 CYLINDER HEAD INSTALLATION 10-16 CYLINDER HEAD DISASSEMBLY 10-9 CAMSHAFT INSTALLATION 10-18 SERVICE INFORMATION GENERAL • To remove the cylinder head, the following parts must be removed: • Exhaust pipes (Section 5). • Engine mounting bolt on rear cylinder head. • Carburetor (Section 4). • Radiator (Section 6). • Camshaft lubricating oil is fed through an oil line. Be sure the hole in the oil line is not clogged. • During assembly, apply molybdenum disulfide to the camshaft holder surfaces to provide initial lubrication. • The cylinder numbering is given below: 10 FRONT SPECIFICATIONS STANDARD SERVICE LIMIT Compression pressure 13 ± 2 kg/cm2 (184 ± 28 psi) — Camshaft Cam height IN 35.335-35.495 mm (1.3911-1.3974 in) 35.3 mm (1.39 in) EX 35.335-35.495 mm (1.3911-1.3974 in) 35.3 mm (1.39 in) Runout — 0.10 mm (0.004 in) End clearance 0.05-0.25 mm (0.002-0.010 in) 0.30 mm (0.012 in) Oil clearance Center 0.030-0.091 mm (0.001-0.004 in) 0.10 mm (0.004 in) Both ends 0.050-0.111 mm (0.002-0.004 in) 0.12 mm (0.005 in) Rocker arm Rocker arm I.D. 12.000-12.018 mm (0.4724-0.4731 in) 12.05 mm (0.474 in) Shoft O.D. 11.966-11.984 mm (0.4711-0.4718 in) 11.93 mm (0.470 in) Valve Valve stem O.D. IN 5.475-5.490 mm (0.2156-0.2161 in) 5.47 mm (0.215 in) EX 5.455-5.470 mm (0.2148-0.2154 in) 5.45 mm (0.214 in) Valve guide I.D. 5.500-5.515 mm (0.2165-0.2171 in) 5.55 mm (0.219 in) Stem-to-guide clearance IN 0.010-0.040 mm (0.0004-0.0016 in) 0.08 mm (0.003 in) EX 0.030-0.060 mm (0.0012-0.0024 in) 0.10 mm (0.004 in) Valve stem runout — 0.05 mm (0.002 in) Valve length IN 89.55 mm (3.526 in) 89.05 mm (3.506 in) EX 89.35 mm (3.518 in) 88.85 mm (3.498 in) Valve seat width 0.99-1.27 mm (0.039-0.050 in) 1.5 mm (0.06 in) 135 Date of Issue: May, 1982 0 HONDA MOTOR CO., LTD 10-1