MAINTENANCE
CarburettorConditions
Y Before any adjustments are made the air filter should be clean and
Functioning, Basic setting, Final setting
the cylinder cowling fitted. Adjusting the carburettor while a dirty
air filter is in use will result in a leaner mixture when the filter is
WARNING! Do not start the saw without the bar,finally cleaned. This can give rise to serious engine damage.
chain and clutch cover (chain brake) assembled.
Y Carefully turn the L and H-jets clockwise to the bottom. Now turn
If you do, the clutch might come loose and causethe jets one turn anti-clockwise. The carburettor is now set to H =
severe injuries.
1 and L = 1.
Y Now start the saw according to the starting instructions and run it
Operationwarm for 10 minutes.
Y The carburettor governs the engine speed via the throttle. Air/fuel areNOTE! If the chain rotates the T screw should be turned anti-
mixed in the carburettor. The air/fuel mixture is adjustable. To takeclockwise until the chain stops.
advantage of the sawOs maximum output the setting must be correct.Y Place the saw on a flat surface so that the bar points away from
Y The satisfactory operation of a catalytic converter depends,you and so that the bar and chain do not come into contact with
among other factors, on the correct adjustment of thethe surface or other objects.
carburettor. Follow carefully the instructions below, using a
Low speed needle L
tachometer to check engine speed.Try to find the highest idling+ 1/4
Y Adjusting the carburettor means the engine is adapted to local
operating conditions, e.g. climate, altitude, petrol and the type ofspeed, turning the low speed
needle L clockwise respectively
2-stroke oil used.
counter-clockwise. When theLH
highest speed has been found,
Y The carburettor has threeturn the low speed needle L 1/4
adjustment possibilities:L
L = Low speed jet.turn counter-clockwise.
NOTE! If the chain rotates in
H = High speed jet.
T = Adjustment screw forthe idling position, turn the idling speed screw counter-clockwise
idling.until the chain stops.
TFinal setting of the idling speed T
Y The fuel quantity required in relation to the air flow, provided byAdjust the idling speed with the screw T. If it is necessary to re-
adjust, first turn the idle speed adjusting screw T clockwise, until the
opening the throttle, is adjusted by the L and H-jets. If they arechain starts to rotate. Then turn, counter-clockwise until the chain
screwed clockwise the air/fuel ratio becomes leaner (less fuel) and
if they are turned anti-clockwise the ratio becomes richer (morestops. A correctly adjusted idle speed setting occurs when the
engine runs smoothly in every position. It should also be good
fuel). A leaner mixture gives a higher engine speed and a richermargin to the rpm when the chain starts to rotate.
mixture give a lower engine speed.
Y The T screw regulates the idling speed. If the screw T is turnedContact your servicing dealer, if the idle speed
clockwise this gives a higher idling speed; anti-clockwise a lowersetting cannot be adjusted so that the chain
idling speed.stops. Do not use the saw until it has been
properly adjusted or repaired.
WARNING! The catalytic converter muffler gets
very hot during and after use. This also appliesHigh speed needle H
during idling. Be aware of the fire hazard,The high speed needle H
especially when handling the saw near flammableinfluences the power of the saw.
substances or vapours.A too lean adjusted high speed
needle H (high speed needle H
Basic setting and running inclosed too much) gives overrevs
and damages the engine. Let
The carburettor is adjusted to a basic setting when the saw is tested at
the factory. The basic setting is: H = 1 turn respective L = 1 turn.the saw run at full speed for
about 10 seconds. Thereafter,
To provide the engineOs components with a good level ofturn the high speed needle H 1/4H
lubrication (running in) the carburettor should be set for aturn counter-clockwise.
richer fuel mixture for the first 3-4 hours of operating. To obtainLet the saw run again at full speed for about 10 seconds and note
this adjust the speed 6-700 rpm under the recommended max.the difference of the enginesound. Repeat this procedure with the
speed.high speed needle H turned 1/4 turn more counter-clockwise. The
saw has now been tested with the following settings: H=0, H=+1/4,
If you do not have the possibility to check the speed using a
tachometer the H-jet should not be set for a leaner mixture than thatH=+1/2 from basic adjustment. At full speed the engine has
produced a different sound for each setting. The high speed needle
stated for the basic setting.
The recommended speed should not be exceeded.H is correctly set when the saw �4-cycles� a little. If the saw �whist-
les� the setting is too lean. If there is too much exhaust gas at the
NOTE! If the chain rotates while idling the T screw should besame time as the saw �4-cycles� much, the setting is too rich. Turn
adjusted anti-clockwise until it stops.
the high speed needle H until the setting sounds correct.
NOTE! For optimum setting of the carburettor, contact a qualified
Fine adjustment
Y When the saw has been �run-in� the carburettor should be finelyservicing dealer who has a revolution counter at his disposal. The
maximum speed recommended must not be exceeded.
adjusted. The fine adjustment should be carried out by
qualified person. First adjust the L-jet, then the idling screw TCorrectly adjusted carburettor
and then the H-jet. The following engine speed applies:A correctly adjusted carburettor means that the saw accelerates
Max. speedIdling speedwithout hesitation and the saw 4-cycles a little at max speed.
355:13 000 rpm2 700 rpmFurthermore, the chain must not rotate at idling. A too lean adjusted
low speed needle L may cause starting difficulties and bad accelera-
Changing the type of fueltion. A too lean adjusted high speed needle H gives lower
Fine tuning may be required if the chain saw, after changing the typepower=less capacity, bad acceleration and/or damage to the engine.
of fuel, performs differently with regard to starting, acceleration, max.A too rich adjustment of the two speed needles L and H gives
speed, etc.acceleration problems or too low working speed.
English � 29 |
ACEC
HUSQVARNA
