Engine, general | ||
Type | Single-cylinder four-stroke, double overhead camshafts driven by roller chain, 4 valves operated by bucket tappets, balancing shaft, liquid-cooled cylinder and cylinder head, integral water pump, 5-speed gearbox and dry sump lubrication. | |
Cylinder bore | mm (in) | 100 (3.94) |
Stroke | mm (in) | 83.0 (3.27) |
Displacement | cc | 652 |
Compression ratio | 11.5 : 1 | |
Power output | kW (hp) | 37 (50) at 6500 rpm |
Max. torque | Nm | 60 at 5000 rpm |
Idle speed | rpm | 1400 |
Max. continuous engine speed | rpm | 7000 |
Max. engine speed | rpm | 7500 |
Crankshaft (main) bearings | Plain bearing | |
Engine lubrication | Dry sump, with oil pump | |
Cylinder | Light alloy, "Nikasil" coated | |
Piston | Cast aluminium with 3 rings | |
Oil filter | Full-flow type | |
Oil pump | 2 trochoid pumps, driven from primary output | |
Oil capacity | l (Imp.pints/ US quarts) | 2.3 (4.05/2.43) |
Oil pressure (idle speed) | bar (psi) | ≥0.5 (7.11) (oil temperature 80°C/176°F) |
Permissible oil consumption | l/100km (miles per Imp. pint/ miles per US quart) | 0.1 (350/590) |
Crank gear | ||
Crankshaft - main bearing play | ||
On installation | mm (in) | 0.030...0.070 (0.0012...0.0028) |
Wear limit | mm (in) | 0.10 (0.004) |
Wear limit, main bearing bore diameter | mm (in) | 46.08 (1.814) |
Wear limit | ||
Main bearing journal diameter | mm (in) | 47.97 (1.888) |
Bearing play | mm (in) | 0.10 (0.004) |
Runout at crankpin | ||
Clutch end | mm (in) | 0.03 (0.001) |
Magnet end | mm (in) | 0.05 (0.002) |
Connecting rod | ||
Wear limit, connecting rod | ||
Radial play | ||
Big end bore | mm (in) | 0.08 (0.003) |
Small end bore | mm (in) | 0.05 (0.002) |
Connecting rod - axial play | ||
On installation | mm (in) | 0.30...0.65 (0.012...0.026) |
Wear limit | mm (in) | 0.80 (0.031) |
Small-end bearing - axial play | ||
On installation | mm (in) | 22.015...22.025 (0.8668...0.8671) |
Wear limit | mm (in) | 22.04 (0.868) |
Compensating shaft | ||
Bearing journals | ||
Wear limit | 19.96 (0.786) | |
Cylinder head | ||
Camshaft journals I/E | mm (in) | 21.967...21.980 (0.8649...0.8654) |
Wear limit | mm (in) | 21.950 (0.8642) |
Camshaft bearing play I/E | mm (in) | 0.020...0.060 (0.0008...0.0023) |
Wear limit | mm (in) | 0.090 (0.0035) |
Valves | ||
Valve clearances with engine cold (max. 35°C/95°F) | ||
Inlet valves | mm (in) | 0.05...0.10 (0.002...0.004) |
Exhaust valves | mm (in) | 0.25...0.30 (0.010...0.012) |
Valve timing (at 3 mm/0.12 in valve clearance) | ||
Inlet opens | 13° after TDC | |
Inlet closes | 25° after BDC | |
Exhaust opens | 25° before BDC | |
Exhaust closes | 13° before TDC | |
Valve head dia. | ||
Inlet | mm (in) | 36 (1.41) |
Exhaust | mm (in) | 31 (1.22) |
Stem dia. | ||
Inlet | mm (in) | 4.90...4.94 (0.193...0.194) |
Wear limit | mm (in) | 4.89 (0.193) |
Exhaust | mm (in) | 4.90...4.94 (0.193...0.194) |
Wear limit | mm (in) | 4.89 (0.193) |
Valve stem play - installed clearance | ||
Inlet | mm (in) | 0.016...0.058 (0.0006...0.0023) |
Wear limit | mm (in) | 0.130 (0.0051) |
Exhaust | mm (in) | 0.031...0.073 (0.0012...0.0029) |
Wear limit | mm (in) | 0.145 (0.0057) |
Valve seat angle | ||
Inlet | ° | 45 |
Exhaust | ° | 45 |
Included valve angle | ||
Inlet | ° | 15 |
Exhaust | ° | 18 |
Valve seat width | ||
Inlet | mm (in) | 1.05...1.35 (0.041...0.053) |
Wear limit | mm (in) | 1.60 (0.063) |
Exhaust | mm (in) | 1.25...1.55 (0.049...0.061) |
Wear limit | mm (in) | 2.2 (0.09) |
Valve guide | ||
Inlet Intl. dia. | mm (in) | 5.006...5.018 (0.1971...0.1976) |
Wear limit | mm (in) | 5.080 (0.2000) |
Exhaust Intl. dia. | mm (in) | 5.006...5.018 (0.1971...0.1976) |
Wear limit | mm (in) | 5.080 (0.2000) |
Bucket tappets (wear limit) | ||
Extl. dia. | mm (in) | 33.400 (1.3150) |
Radial clearance in cylinder head | mm (in) | 0.200 (0.0079) |
Guide dia. in cylinder head | mm (in) | 33.600 (1.3229) |
Valve spring | ||
On installation (free length) | mm (in) | min. 40.5 (1.60) |
Wear limit | mm (in) | 39.0 (1.54) |
Camshafts | ||
Wear limit | ||
Inlet and exhaust | ||
Bearing journal diameter | mm (in) | 21.95 (0.864) |
Cam height I | mm (in) | 39.35...39.45 (1.545...1.553) |
Cam height E | mm (in) | 39.15...39.25 (1.541...1.545) |
Wear limit I | mm (in) | 39.25 (1.545) |
Wear limit E | mm (in) | 39.05 (1.537) |
Bearing bore dia. in camshaft mount | mm (in) | 22.040 (0.8677) |
Oil pressure control valve | ||
Coil spring length, relaxed | mm (in) | min. 14.0 (0.55) |
Oil retaining valve | ||
Coil spring length, relaxed | mm (in) | min. 14.5 (0.57) |
Pistons | ||
Piston diameter | ||
"A" | ||
On installation | mm (in) | 99.975...99.985 (3.9361 ...3.9365) |
Wear limit | mm (in) | 99.940 (3.9347) |
Installed clearance | mm (in) | 0.015...0.040 (0.0006...0.0016) |
Wear limit | mm (in) | 0.090 (0.0035) |
"B" | ||
On installation | mm (in) | 99.985...99.995 (3.9365...3.9369) |
Wear limit | mm (in) | 99.950 (3.9351) |
Installed clearance | mm (in) | 0.015...0.040 (0.0006...0.0016) |
Wear limit | mm (in) | 0.090 (0.0035) |
Piston rings | ||
1st groove Rectangular-section ring | ||
Ring thickness | mm (in) | 1.2 (0.05) |
Ring thickness wear limit | mm (in) | 1.15 (0.045) |
End gap | mm (in) | 0.2...0.4 (0.008...0.016) |
End-gap wear limit | mm (in) | 1.0 (0.04) |
Groove-height wear limit | mm (in) | 1.30 (0.051) |
Ring float | mm (in) | 0.03...0.065 (0.0012...0.0026) |
Ring float, wear limit | mm (in) | 0.15 (0.045) |
2nd groove Micro-taper ring | ||
Ring thickness | mm (in) | 1.5 (0.06) |
Ring thickness wear limit | mm (in) | 1.45 (0.057) |
End gap | mm (in) | 0.2...0.4 (0.008...0.016) |
End-gap wear limit | mm (in) | 1.0 (0.04) |
Groove-height wear limit | mm (in) | 1.6 (0.06) |
Ring float | mm (in) | 0.03...0.065 (0.0012...0.0026) |
Ring float, wear limit | mm (in) | 0.15 (0.045) |
3rd groove Spring-steel oil control ring | ||
End gap | mm (in) | 0.2...0.4 (0.008...0.016) |
End-gap wear limit | mm (in) | 1.0 (0.04) |
Groove-height wear limit | mm (in) | 2.6 (0.10) |
Ring float | mm (in) | 0.03...0.065 (0.0012...0.0026) |
Ring float, wear limit | mm (in) | 0.15 (0.045) |
Piston pin | ||
Piston pin dia. | ||
Wear limit | mm (in) | 21.98 (0.865) |
Piston-pin play | ||
in small end bore | mm (in) | 0.015...0.029 (0.0006...0.0011) |
Wear limit | mm (in) | 0.050 (0.0020) |
in bore in piston | mm (in) | 0.012...0.021 (0.0005...0.0008) |
Wear limit | mm (in) | 0.050 (0.0020) |
Cylinder | ||
Bore | ||
Cylinder "A" | mm (in) | 100.000...100.012 (3.9371...3.9376) |
Wear limit | mm (in) | 100.03 (3.9382) |
Bore | ||
Cylinder "B" | mm (in) | 100.012...100.024 (3.9376...3.9380) |
Wear limit | mm (in) | 100.04 (3.9387) |
Timing chain | ||
Wear limit | ||
Distance from sealing face of plug to pis- | ||
ton of chain tensioner | mm (in) | 9.0 (0.35) |
Clutch and gearbox | ||
Clutch friction plates (8 plates) | ||
Size per plate on installation | mm (in) | 3.45...3.55 (0.136...0.140) |
Wear limit for thickness of plate assembly (total) | mm (in) | 27.5 (1.082) |
Copper springs | ||
Wear limit at 190 N | mm (in) | 27.4 (1.079) |
Oil pump | ||
Oil pumps | primary/secondary | |
Housing depth (primary) | mm (in) | 14 (0.6) |
Housing depth (secondary) | mm (in) | 19 (0.7) |
Wear limit, installed clearance (radial) | mm (in) | 0.25 (0.010) |
Wear limit, installed clearance (axial) | mm (in) | 0.25 (0.010) |