KTM 450 SMR Motorcycle User Manual


 
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 idlex
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Screw in the idle adjusting screw until it stops and then to the prescribed basic
setting.
Specification
Idle mixture adjusting screw
Open 1.5turns
Adjustment tool for mixture control screw (77329034000)
Run the engine until warm.
Specification
Warm-up time 싩5min
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… 1650rpm
Turn the idle adjusting screw
slowly until the idle speed begins to fall.
Note the position and turn the idle adjusting screw slowly counterclockwise until
the idle speed falls.
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.
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… 1650rpm
Info
Following extreme air temperature or altitude changes, adjust the idle speed
again.