21
TECHNICAL DATA
103
21.1
Engine
Design
1-cylinder 4-stroke engine, water-cooled
Displacement
449.9 cm³ (27.455 cu in)
Stroke
63.4 mm (2.496 in)
Bore
95 mm (3.74 in)
Compression ratio
12.75:1
Idle speed
2,250… 2,350 rpm
Control
OHC, 4 valves controlled via rocker arm
Valve diameter, intake
40 mm (1.57 in)
Valve diameter, exhaust
33 mm (1.3 in)
Valve clearance
Intake at: 20 °C (68 °F)
0.10… 0.15 mm (0.0039… 0.0059 in)
Exhaust at: 20 °C (68 °F)
0.12… 0.17 mm (0.0047… 0.0067 in)
Crankshaft bearing
2 cylinder roller bearing
Conrod bearing
Slide bearing
Piston pin bearing
Not a bearing bush - DLC-plated piston pins
Pistons
Forged light alloy
Piston rings
1 compression ring, 1 oil scraper ring
Engine lubrication
Pressure circulation lubrication with two Eaton pumps
Primary transmission
31:76
Clutch
Multidisc clutch in oil bath, hydraulically activated
Gearbox (SX
‑
F EU)
4-gear, claw shifted
Gearbox (All US models)
5-gear, claw shifted
Transmission ratio (SX
‑
F EU)
First gear
16:32
Second gear
18:30
Third gear
20:28
Fourth gear
22:26
Transmission ratio (All US models)
First gear
16:32
Second gear
18:30
Third gear
20:28
Fourth gear
22:26
Fifth gear
24:24
Alternator
12 V, 75 W
Ignition
Contactless controlled fully electronic ignition with digital igni-
tion adjustment
Spark plug
NGK LMAR9AI-8
Spark plug electrode gap
0.8 mm (0.031 in)
Cooling
Water cooling, permanent circulation of coolant by water pump
Starting aid
Electric starter
21.2
Engine tightening torques
Screw, oil jet for piston cooling
M4
2 Nm (1.5 lbf ft)
Loctite
®
243™
Oil nozzle for clutch lubrication
M5
2 Nm (1.5 lbf ft)
Loctite
®
243™
Oil nozzle, piston cooling
M5
2 Nm (1.5 lbf ft)
Loctite
®
243™
Oil nozzle, rocker arm lubrication
M5
2 Nm (1.5 lbf ft)
Loctite
®
243™
Pulse generator screw and cable
retainer
M5
6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, bearing retainer
M5
6 Nm (4.4 lbf ft)
Loctite
®
243™
Screw, clutch spring retainer
M5
6 Nm (4.4 lbf ft)
–
Screw, gear position sensor
M5
5 Nm (3.7 lbf ft)
Loctite
®
243™
