CARBURETTOR
English – 33
!
H
L
+ 1/4
Low speed jet L
Find the highest idling speed by slowly turning the L-screw
clockwise then anti-clockwise. When the highest speed has
been found, turn the L-screw anti-clockwise 1/8 - 1/4 turn.
WARNING! If the chain turns when idling, the
T-screw should be turned anti-clockwise until
the chain stops.
Fine adjustment of idling T
Setting the idling speed is carried out using the screw
marked T. If adjustment is necessary, screw in (clockwise)
the idling screw T with the motor running, until the chain
starts to turn. Then screw out (anti-clockwise) until the chain
stops moving. The correctly set idling speed is when the
motor runs smoothly in all positions with a good margin from
the speed where the chain starts to move.
WARNING!
Do not use the saw until it has been
adjusted so that the chain is still.
High speed jet H
The high speed jet screw H influences the chainsaws power
and engine speed. If the H-screw is set too weak (H screw
too far in) the saw will over-rev with engine damage as a
consequence. Run the saw at full throttle for 10 seconds.
Then turn the H-screw anti-clockwise 1/4 turn. Run the saw
again at full throttle for 10 seconds and listen to the difference
in the max. overspeed. Repeat this procedure again with the
H-screw turned a further 1/4 turn anti-clockwise.
You have now run the saw at settings H ±0, H = +1/4 and H
= +1/2 from the base settings. At full throttle the motor will
have sounded different at each setting. The H-screw is
correctly adjusted when the saw ”burbles” (four-strokes) a
little. If the saw ”shrieks” then the setting is too weak. If there
is a lot of smoke from the exhaust at the same time as the
motor burbles then the setting is too rich. Turn the H-screw
clockwise to the setting that sounds right.
NOTE!
For optimal setting, a tachometer should be
used. The recommended maximum
overspeed should not be exceeded.
Correctly adjusted carburettor
A correctly adjusted carburettor means that the saw
accelerates without hesitation and the saw burbles a little at
full throttle. In addition the chain should not turn when idling.
If the L-screw is set too weak this can make the saw difficult
to start and cause poor acceleration. If the H-screw is set too
weak the saw will have less power, poor acceleration and/or
motor damage. An over rich setting of either L or H screws
will cause acceleration problems or too low working speed.
