ENGLISH
43
TECHNICAL DATA – ENGINE
»
ENGINE
250 SX-F
450 SX-F
Design
Liquid-cooled single cylinder 4-stroke engine
Displacement
249.51 ccm
449.3 ccm
Bore/Stroke
76 / 55 mm
97 / 60.8 mm
Ratio
12.8 : 1
12.5 : 1
Fuel
unleaded fuel with at least RON 95
Valve timing
4 valves controlled by finger levers and 2 camshafts,
driven by a pair of spur gears and a tooth-type chain
Camshaft
05
773.36.009.100 / 773.36.010.100
Valve diameter Intake
30.9 mm
40.4 mm
Valve diameter Exhaust
26.5 mm
31.7 mm
Valve clearence cold Intake 0.10 - 0.20 mm
0.15 mm
Valve clearence cold Exhaust 0.12 - 0.22 mm
0.20 mm
Crank shaft bearing
2 cylinder roller bearings
Connecting rod bearing
needle bearing
Top end bearing
bronze bushing
Piston
alluminium alloy forged
Piston rings
1 compression ring, 1 oil scraper ring
Engine lubrication
pressure circulation lubrication with 2 rotor pumps
Engine oil
full synthetic oil (see below)
Quantity of engine oil
1.1 liters
1.3 liters
Primary drive
22:68
29:74
Transmission claw shifted
6-speed
4-speed
1st gear
13:32
17:32
2nd gear
15:30
19:30
3rd gear
17:28
21:28
4th gear
19:26
23:26
5th gear
21:25
-
6th gear
22:24
-
Ignition system
contactless DC-CDI ignition with digital advanced system by KOKUSAN
Generator
no generator
42 Watts at 10.000 rpm
Spark plug
NGK CR 9 EBK
Cooling system
liquid cooled, permanent rotation of cooling liquid through mechanically driven water pump
Cooling liquid
1.2 liters, 50% antifreeze, 50% destilled water, at least -25° (-13° F)
Starting device
kick starter
E-starter
Engine oil
Only use fully synthetic engine oils that meet the JASO MA quality requirements
(see information on the can).
KTM recommends Motorex Power Synt 4T in the 10W/50 viscosity (for
temperatures over 5°C, 41°F) or 5W/40 (for temperatures under 5°C, 41°F).
Poor oil quality or minor quantity cause early engine-wear.
5°C
41°F
10W/50
5W/40
JASO T903 MA
TEMPERATURE