Owner's Manual

The carburetor does not have a high
speed adjusting screw (H screw) but is
designed to provide an optimum fuel-air
mixture under all operating conditions.
The maximum engine speed specified
for machines with a conventional
carburetor does not apply to this version.
No provision is made for adjustment of
maximum engine speed. On these
machines it is only possible to correct
the idling speed within narrow limits.
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••
•
Check the air filter and clean it if
necessary.
Carefully screw the low speed screw (L)
down onto its seat.
Now open it one turn counterclockwise
(standard setting, L = 1)
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••
•
Warm up the engine.
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed screw
(L).
Turn screws only very slightly and
carefully - even minor changes have a
noticeable effect on the engine’s running
behavior.
Engine stops while idling:
’L’ screw must be one turn open.
Turn the idle speed screw (LA) clockwise
until chain begins to run -
then back off the screw one quarter
of a turn.
Chain runs when engine is idling
’L’ screw must be one turn open.
Turn the idle speed screw (LA)
counterclockwise until chain
stops running -
then turn screw another quarter turn in
the same direction.
Erratic idling behaviour,
poor acceleration
(even though ’L’ screw in one turn
open)
Idle setting is too lean.
Turn the low speed screw (L) counter-
clockwise until engine runs and
accelerates smoothly.
L
LA
143BA028 KN
Adjusting Carburetor
with two adjusting screws
Motor Management
Exhaust emissions are controlled by the
design of the fundamental engine
parameters and components
(e.g. carburetion, ignition, timing and
valve or port timing) without the addition
of any major hardware.
LLA
017, 018 39