KTM 250 SX - Manual (Page 121)

9-37C
Repair manual KTM 250 / 300 / 380
Art No 3206004 -E
Engine
250 MXC/EXC
300 MXC/EXC
Desgin
Liquid-cooled single-cylinder two-str
oke engine with
KTM T
win
V
alve
C
ontr
ol exhaust system and
K
TM
T
or
que
C
hamber
Piston displacement
249 ccm
297 ccm
Bor
e / str
oke
66,4 / 72 mm (2.62 / 2.84 in)
72 / 73 mm (2.84 / 2.88 in)
Fuel
unleaded SUPER fuel, r
esear
ch octane no 95, mixed with high-grade, two- str
oke oil
Oil / gasolino ratio
1:40 – 1:60 when using high grade, two- str
oke oil. When in dout, please contact your importer or use 1:40
mix ratio to be on the safe side
Crankshaft bearing
1 deep-gr
oove ball bearing / 1 cylinder r
oller bearing
Connecting r
od bearing
needle bearing
Piston pin bearing
needle bearing
Piston
cast piston
for
ged piston
Piston ring
two plain compr
ession rings
Dimension
“X“
0 + 0,1 mm (0 + 0.004 in)
Ingition timing
1,9 mm vor OT
1,94 mm vor OT
Spark plug
NGK
BR
7 ES
Electr
ode gap
0,60 mm
Dimension
“Z“
49,5 mm (0.024 in)
46 mm (1.7 in)
TVC start open
5000/min
5900/min
TVC fully open
7000/min
7750/min
Primary drive
straight cut spur gears, primary ratio 25:72
Clutch
multiple disc clutch in oil bath, hydraulically operated (Shell HF-E15
Transmission
5 speed, claw actuated
Gear ratio
EXC
MXC
EXC
MXC
1 st
gear
15:29
15:29
15:29
15:29
2 nd
gear
18:26
17:27
18:26
18:26
3 rd
gear
19:22
19:25
19:22
19:24
4 th
gear
21:20
21:23
21:20
21:23
5 th
gear
23:18
23:21
23:18
23:21
Gear lubrication
0,8 l engine oil 10W
-40
ailable chain spr
ockets
13Z / 14Z / 15Z for chain
5
/ 8
x
1
/ 4
"
Coolant
1.3 liters, 40% antifr
eeze, 60% water
, at least -25 °C (-13 °F)
Ignition system
KOKUSAN 2K-3
Generator output
12V 110W
Ignition system USA (MXC)
KOKUSAN
2K-2
Generator output
12V 40W
Carbur
etor
flat-slide carbur
etor
, carbur
etor setting see table
Air
- filter
wet foam type air filter insert
(upper edge piston - upper edge cylinder) (height of the contr
ol flap)
TECHNICAL DA
TA
- ENGINE 250/300 MXC / EXC 2003