KTM 450 SMR - Manual (Page 63)

MAINTENANCE WORK ON CHASSIS AND ENGINE
61

Carburetor - idle
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The idle setting of the carburetor has a big influence on the starting behavior, stable
idling and the response to throttle opening. That means that an engine with a correctly
set idle speed is easier to start than if the idle is set wrongly.
Info
The carburetor and its components are subject to increased wear caused by en-
gine vibration. Wear can result in malfunctioning.
The idle speed is adjusted with the adjustment screw ‘  .
The idle mixture is adjusted with the idle mixture adjustment screw ‘  .

Carburetor - adjusting idle ‘
x
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ಥ Screw in the idle adjusting screw ‘  until it stops and then to the prescribed basic
setting.
Specification
Idle mixture adjusting screw
Open 1.5 ‘turns
Adjustment tool for mixture control screw (77329034000)
ಥ Run the engine until warm.
Specification
Warm-up time 싩‘5‘min
ಥ Adjust the idle speed with the adjusting screw ‘  .
Specification
Choke function activated ಥ‘The choke lever is pushed in to the stop. ( P. 11)
Idle speed 1600… 1650 ‘rpm
ಥ Turn the idle adjusting screw ‘  slowly until the idle speed begins to fall.
ಥ Note the position and turn the idle adjusting screw slowly counterclockwise until
the idle speed falls.
ಥ Adjust to the point between these two positions with the highest idle speed.
Info
If there is a big engine speed rise, reduce the idle speed to a normal level
and repeat the above steps.
The extreme sport motocyclist will set the mixture about 1/4 of a turn back
from this ideal value (leaner, in a clockwise direction) since the engine be-
comes hotter in sporting use.
If the procedure described here does not lead to satisfactory results, the
cause may be a wrongly dimensioned idling jet.
If you can turn the idle adjusting screw to the end without any change of
engine speed, you have to fit a smaller idling jet.
The idle adjusting screw must not be opened more than two turns. If more
than two turns are necessary (rich mixture), use a larger idling jet.
After changing the idling jet, start from the beginning with the adjusting
steps.
ಥ Adjust the idle speed with the adjusting screw ‘  .
Specification
Choke function activated ಥ‘The choke lever is pushed in to the stop. ( P. 11)
Idle speed 1600… 1650 ‘rpm
Info
Following extreme air temperature or altitude changes, adjust the idle speed
again.