•
The carburetor has three adjustment controls: L (low
jet speed), H (high jet speed) and T (idle adjustment
screw).
T
•
The L- and H-jets are used to adjust the supply of
fuel to match the rate that air is admitted, which is
controlled with the throttle. If they are screwed
clockwise the air/fuel ratio becomes leaner (less fuel)
and if they are turned anti-clockwise the ratio
becomes richer (more fuel). A lean mixture gives a
higher engine speed and a rich mixture gives a lower
engine speed.
•
The T-screw regulates the throttle setting at idle
speed. If the T-screw is turned clockwise this gives a
higher idle speed; turning it anti-clockwise gives a
lower idle speed.
Basic settings and running in
The basic carburetor settings are adjusted during testing
at the factory.
CAUTION: Avoid running at a too high
speed during the first 10 hours.
CAUTION: If the saw chain rotates while it
idles the T-screw must be turned anti-
clockwise until the saw chain stops.
Recommended idle speed: 2900rpm
To adjust the carburetor
When the product has been "run-in" the carburetor
should be finely adjusted. The fine adjustment should be
carried out by a qualified person.
Note: Fine tuning may be required if the chainsaw, after
changing the type of fuel, performs differently during
start, acceleration, maximum speed etcetera.
First adjust the L-jet, followed by the idiling T-screw and
finally the H-jet.
26
H
L
CAUTION: Do not attempt to adjust the L-
and H-jets beyong either stop as this could
cause damage.
1. Make sure that the air filter is clean and the cylinder
cover is fitted before you make any adjustments.
CAUTION: If you adjust the carburetor
while a dirty air filter is in use this will
result in a leaner mixture next time the
filter is cleaned. This can give rise to
serious engine damage.
2. Start the product and let it warm up for 10 minutes.
See instructions under heading
on page 15
3. Place the product on a flat surface so that the guide
bar points away from you and so that the guide bar
and saw chain do not come in contact with the
surface or other objects.
4. Turn the low speed L-jet clockwise until it stops.
5. If the engine accelerates poorly or idles unevenly,
turn the low speed L-jet anti-clockwise until you
achieve good acceleration and idling.
6. If it is necessary to re-adjust, turn the T-screw
clockwise until while the engine is running until the
saw chain starts to rotate.
7. Turn anti-clockwise until the saw chain stops.
Note: When the idle speed is correctly adjusted the
engine should run smoothly in every position and the
engine speed should be safely below the speed at
which the saw chain starts to rotate.
WARNING: Contact your servicing
dealer if the idle speed setting can not
be adjusted so that the saw chain stops
at idle. Do not use the product until it has
been properly adjusted or repaired.
At the factory the engine is adjusted at sea level. When
working at a high altitude or in different weather
conditions, temperatures and atmospheric humidity, it
may be necessary to make minor adjustments to the
high speed H-jet. When test run at the factory, the high
speed H-jet is set so that the engine satisfies the
applicable legal requirements at the same time as it
achieves maximum performance. The high speed H-jet
of the carburetor is then locked using a limiter cap in the
fully screwed out position. The limiter cap limits the
potential to adjust the high speed H-jet to at most 1/2
turn.
CAUTION: If the high speed H-jet is screwed
in too far, it may damage the piston/cylinder.
When the carburetor is correctly adjusted the product
accelerates without hesitation and 4-cycles a little at
To start the product
321 - 004 - 27.09.2017