19
CARBURETOR
146
19.1
Choke
B01664-10
Choke
1
is fitted on the left side of the carburetor.
Activating the choke function frees a drill hole in the carburetor through which the
engine can draw extra fuel. This results in a richer fuel-air mixture, which is needed
for a cold start.
Info
If the engine is warm, the choke function must be deactivated.
Possible states
• Choke function activated
–
The choke lever is pulled out to the stop.
• Choke function deactivated
–
The choke lever is pushed in to the stop.
19.2
Carburetor - adjusting idle
B01675-10
–
Screw idle air adjusting screw
2
all the way in and turn to the specified basic set-
ting.
Guideline
Idle air adjusting screw
Open
2.0 rotations
–
Run the engine until warm.
Guideline
Warm-up time
≥
5 min
Danger
Danger of poisoning
Exhaust gases are toxic and inhaling them may result
in unconsciousness and/or death.
–
When running the engine, always make sure there is sufficient ventila-
tion, and do not start or run the engine in an enclosed space without an
effective exhaust extraction system.
–
Adjust the idle speed with adjusting screw
1
.
Guideline
Choke function deactivated
–
The choke lever is pushed in to the stop.
Idle speed
1,400… 1,500 rpm
–
Turn idle air adjusting screw
2
slowly clockwise until the idle speed starts to drop.
–
Note the position and turn the idle air 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.
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 air adjusting screw to the end without any change of
engine speed, you have to mount a smaller idling jet.
After changing the idling jet, start from the beginning with the adjusting
steps.
Following extreme air temperature or altitude changes, adjust the idle speed
again.