2-3 6. MAINTENANCE STANDARDS • ENGINE Unit: mm (in) Parts Item Standard Service limit Engine Idle speed (in neutral) 750 ± 50 min–1(rpm) – Trolling speed 650 ± 50 min–1(rpm) – Cylinder compression [kPa (kgf/cm2, psi) at 200 min–1(rpm)] 1,532 – 1,728 (15.6 – 17.6, 222 – 250) 930 (9.5, 135) Compression gap between cylinders [kPa (kgf/cm2, psi)] – 200 (2.0, 28) Spark plugs Gap 1.0 – 1.1 (0.039 – 0.043) 1.3 (0.051) Valves Valve clearance IN 0.21 – 0.25 (0.008 – 0.010) – EX 0.28 – 0.32 (0.011 – 0.013) – Overall length IN 108.7 – 109.5 (4.28 – 4.31) – EX 108.3 – 109.1 (4.26 – 4.30) – Valve O.D. IN 34.85 – 35.15 (1.372 – 1.384) – EX 29.85 – 30.15 (1.175 – 1.187) – Stem O.D.
IN 5.475 – 5.485 (0.2156 – 0.2159) 5.445 (0.2144) EX 5.450 – 5.460 (0.2146 – 0.2150) 5.420 (0.2134) Stem-to-guide clearance IN 0.030 – 0.055 (0.0012 – 0.0022) 0.08 (0.003) EX 0.055 – 0.080 (0.0022 – 0.0031) 0.11 (0.004) Valve seats Seat width IN/EX 1.25 – 1.55 (0.049 – 0.061) 2.0 (0.08) Seat installation height IN/EX 44.0 – 44.6 (1.73 – 1.76) – Valve guides Guide I.D. IN/EX 5.51 – 5.53 (0.217 – 0.218) 5.55 (0.219) Guide extrusion amount IN 15.2 – 16.2 (0.60 – 0.64) – EX 15.5 – 16.5 (0.61 – 0.65) – Valve springs Free length IN 49.64 (1.954) – EX 49.64 (1.954) – Rocker arms Rocker arm I.D. IN 17.019 – 17.035 (0.6700 – 0.6707) – EX 17.012 – 17.039 (0.6698 – 0.6708) – Rocker arm shaft O.D.
IN/EX 16.983 – 16.994 (0.6686 – 0.6690) – Rocker arm-to-rocker arm shaft clearance IN 0.025 – 0.052 (0.0010 – 0.0020) 0.08 (0.003) EX 0.018 – 0.056 (0.0007 – 0.0022) 0.08 (0.003) Pistons Skirt O.D. A 86.98 – 86.99 (3.4244 – 3.4248) 86.93 (3.4224) B 86.97 – 86.98 (3.4240 – 3.4244) 86.92 (3.4220) Piston-to-cylinder clearance 0.02 – 0.04 (0.001 – 0.002) 0.05 (0.002) Piston pin bore I.D. 21.960 – 21.963 (0.8646 – 0.8647) –