KTM 144 SX Motorcycle User Manual


 
ENGLISH
34
MAINTENANCE WORK ON CHASSIS AND ENGINE »
Adjusting the engine characteristic via the ignition curve (125/144/250)
2 ignition curves (PERFORMANCE and SOFT) are stored in the digital box. The
PERFORMANCE ignition curve is activated in the condition at delivery. The SOFT
ignition curve can easily be activated by disconnecting the socket connector
under the tank.
To change the ignition curve, remove the seat and tank.
A) PERFORMANCE (higher engine performance) socket connector connected
B) SOFT (better driveability) socket connector disconnected
You can also change the ignition curve via the handlebar switch (Power Parts)
while driving.
Adjusting the engine characteristic via the auxiliary spring (250) *
The engine characteristic can be modified through various thicknesses of the
auxiliary spring [1]. An auxiliary spring designed for „good driveability“ (smooth
power application) is mounted in the condition at delivery.
One of the auxiliary springs can be mounted if you prefer an „even smoother
power application“ or an „aggressive engine characteristic“.
Auxiliary spring for good driveability (mounted in condition at delivery)
Spare part number 546.37.072.300, YELLOW color mark
Auxiliary spring for an even smoother power application (included in scope of
supply) Spare part number 548.37.072.100, GREEN color mark
Auxiliary spring for aggressive engine characteristic (included in scope of sup-
ply). Spare part number 548.37.072.000, RED color mark
To mount, tilt the motorcycle approx. 45° to the left, remove both screws [2],
lift off the closing cover [3] and remove the springs including the spring insert
[4] from the clutch cover. Pull both springs off the spring insert, mount the
auxiliary spring [1] and control spring [5] and slide both into the clutch cover
until the recess in the spring insert [4] engages in the rocker arm. Check the
O-ring in the closing cover mount the closing cover, ensuring that the dolly
screw [6] engages in the auxiliary spring.
Make sure you do not turn the dolly screw since this will impair the engine
characteristic.
Be careful not to turn the spring dolly [6], otherwise the engine characteris-
tic will deteriorate.
You can also change the engine characteristic through the interaction between
the ignition curve, auxiliary spring (250 only) and exhaust. The following table
shows examples of possible combinations. Further combinations can be
adjusted at random depending on the driving requirements.
250 SX 2008
Engine performance
– –
Standard setting
++ +
Driveability
+ + +
Standard setting
––
Ignition curve
soft soft
performance
performance performance
Auxiliary spring (250/300)
green yellow
yellow
yellow red
Exhaust
250 SX standard 250 SX standard
250 SX standard
250 SXS 250 SXS
Example of application
extremely difficult
track conditions:
very selective, very
hard, hardly any trac-
tion, very tiring
difficult track
conditions:
selective, not much
traction, tiring
average track
conditions
good track conditions:
nonskid roadway, well
prepared, MX special
stage
special track
conditions:
deep sand, very fast
track routing, very well-
prepared track
A
B
5
2
2
6
4
1
2
3
5
6