English – 37
Carburettor
Low speed jet L
Find the highest idling speed by slowly turning the
low speed screw clockwise then anticlockwise.
When the highest speed has been found, turn the
L-screw anticlockwise 1/8 - 1/4 of a turn.
Fine tuning of idling T
The idling speed is set with the screw marked T.
If adjustment is necessary, screw in (clockwise)
the idling screw T with the engine running until the
chain begins to go round. Now screw out (anticlock-
wise) until the chain stops turning. A correctly set
idling speed is when the engine runs smoothly in all
positions with a good margin to the speed when the
chain starts to turn.
High speed jet H
The high speed jet H affects the chainsaw’s power
and speed. A too lean high speed jet setting (H-
jet screwed in too far) gives over revving on the
saw, resulting in damage to the engine. Run the
chainsaw at full throttle for about 10 seconds. Then
turn the H-screw anticlockwise 1/4 of a turn. Run
the chainsaw again at full throttle for approx. 10
second seconds and listen to the difference in the
overspeed. Repeat this procedure with the H-screw
turned an additional 1/4 of a turn anticlockwise. You
have now run the chainsaw at H ±0, H = +1/4, and
H =+1/2 from the basic settings. At full throttle the
engine will have sounded different for each setting.
The H-screw is set correctly when the chainsaw
“splutters” somewhat. If the saw “screams” then
the setting is too lean. If the muffler emits a lot of
smoke, at the same time as the chainsaw splutters
a lot, then the setting is too rich. Turn the H-screw
clockwise until you find the setting that sounds
right.
NOTE! If the chain goes round at idling speed
the T-screw should be turned anticlockwise until
it stops.
WARNING!
Do not use the chainsaw until it has
been adjusted to prevent the chain
going round at idling speed.
NOTE! A tachometer should be used to achieve
an optimal setting. The recommended max.
overspeed must not be exceeded.
H
L
+ 1/4
Correctly adjusted carburettor
A correctly adjusted carburettor means that the
chainsaw accelerates without hesitation and that
it splutters somewhat at full throttle. In addition,
the chain should not go round at idling speed. If
the L-screw is set too lean this can cause starting
problems and poor acceleration. If the H-screw is set
too lean this will give the chainsaw less power, poor
acceleration, and/or will damage the engine. If both
the L and H screws have an over-rich setting this will
give acceleration problems or reduce the working
speed.
