11.6 Technical data R 850 C R 1200 C Valves Included angle between valves ° 41 Valve clearances with engine cold (max. 35 °C/95 °F) Inlet valve mm (in) Exhaust valve mm (in) 0.15 (0.006) 0.30 (0.012) Valve timing Inlet opens Inlet closes Exhaust opens Exhaust closes At zero valve clearance and 3 mm (0.12 in) valve lift 17° after TDC 15° after BDC 15° before BDC 17° before TDC Tolerance ± 3° Valve head dia. Inlet mm (in) Exhaust mm (in) 32 (1.26) 27 (1.06) 34 (1.34) 29 (1.14) Stem dia.
Inlet mm (in) Wear limit mm (in) Exhaust mm (in) Wear limit mm (in) 4.966...4.980 (0.1955...0.1960) 4.946 (0.1947) 4.956...4.970 (0.1951...0.1956) 4.936 (0.1943) Valve head edge thickness Inlet mm (in) Wear limit mm (in) Exhaust mm (in) Wear limit mm (in) 1.00 ±0.2 (0.04 ±0.008) 0.5 (0.02) 1.00 ±0.2 (0.04 ±0.008) 0.5 (0.02) Max. runout of valve head at valve seat Inlet, exhaust mm (in) 0.035 (0.0014) Valve seat ring Valve seat angle Inlet Exhaust 45° 45° Valve seat width Inlet mm (in) Wear limit mm (in) Exhaust mm (in) Wear limit mm (in) 1.1 ± 0.15 (0.043 ±0.006) 2.5 (0.10) 1.4 ± 0.15 (0.055 ±0.006) 3.0 (0.12) Valve seat extl. dia.
(dimension for machining seat) Inlet mm (in) Exhaust mm (in) 31.4 ±0.1 (1.24 ±0.004) 26.4 ±0.1 (1.04 ±0.004) 33.4 ±0.1 (1.32 ±0.004) 28.4 ±0.1 (1.12 ±0.004) Seat ring dia. (oversize +0.2 mm/+0.008 in) Inlet mm (in) Exhaust mm (in) 34.634...34.650 (1.3635...1.3642) 30.134...30.150 (1.1864...1.1870) 36.617...36.633 (1.4416...1.4422) 32.134...32.150 (1.2651...1.2658) Seat dia. in cyl. head (oversize +0.2 mm/+0.008 in) Inlet mm (in) Exhaust mm (in) 34.500...34.525 (1.3583...1.3592) 30.000...30.025 (1.1811...1.1821) 36.500...36.525 (1.4370...1.4380) 32.000...32.025 (1.2599...1.2608)