Maintenance, Fine adjustment, Conditions – Husqvarna 365 User Manual

Page 30: Low speed jet l, Fine adjustment of the idle speed t, High speed jet h, Correctly adjusted carburettor

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30 –

English

MAINTENANCE

Fine adjustment

When the machine has been ”run-in” the carburettor should
be finely adjusted. The fine adjustment should be carried out
by a qualified person. First adjust the L-jet, then the idling
screw T and then the H-jet.

The recommended engine speeds are as follows:

Conditions

Before any adjustments are made the air filter should be
clean and the cylinder cover fitted. Adjusting the
carburettor while a dirty air filter is in use will result in a
leaner mixture next time the filter is cleaned. This can give
rise to serious engine damage.

Carefully turn the L and H-jets clockwise as far as they will
go. Now turn the jets one turn anti-clockwise. The
carburettor is now set to H = 1 and L = 1.

Now start the machine according to the starting
instructions and let it warm up for 10 minutes. CAUTION!
If the chain rotates while idling the T-screw must be
turned anti-clockwise until the chain stops.

Place the machine on a flat surface so that the bar points
away from you and so that the bar and chain do not come
into contact with the surface or other objects.

Low speed jet L

Try to find the highest idle speed by turning the low speed jet
L clockwise then anti-clockwise. When the highest speed has
been found, turn the low speed jet L 1/4 turn anti-clockwise.

CAUTION! If the chain rotates while idling the T-screw
must be turned anti-clockwise until the chain stops.

Fine adjustment of the idle speed T

Adjust the idle speed using the idle adjustment screw T, if it is
necessary to readjust. First turn the idle adjustment screw T
clockwise until the cutting attachment starts to rotate. Then turn
the screw anticlockwise until the cutting attachment stops. The
idle speed is correctly adjusted when the engine will run
smoothly in every position. The idle speed should also be well
below the speed at which the cutting attachment starts to rotate.

High speed jet H

The high speed jet H influences the power and engine
speed of the machine. If the high speed jet is set too rich
(H-jet screwed in too far) the machine will over-rev and
this will damage the engine. Run the machine at full
throttle for about 10 seconds. Then turn the H-jet 1/4 turn
anti-clockwise. Run the machine at full throttle for another
10 seconds or so and listen to the difference in the fast idle
speed. Repeat this procedure with the H-jet turned a
further 1/4 turn anti-clockwise.

You have now run the machine at settings of H =

±0, H=+1/

4, H=+1/2 relative to the basic settings. At full throttle the
engine has sounded different for each setting. The H-jet is
correctly adjusted when the machine burbles a little. If the
machine ”screams” then the machine is set too lean. If the
muffler emits a lot of smoke and the machine burbles a lot
then the setting is too rich. Turn the H-jet clockwise until
the setting sounds right

CAUTION! To ensure correct adjustment you should enlist a
qualified mechanic who has access to a tachometer. The
recommended maximum fast idle speed must not be
exceeded.

Correctly adjusted carburettor

When the carburettor is correctly adjusted the machine
accelerates without hesitation and 4-cycles a little at full
throttle. It is also important that the chain does not rotate at
idle. If the L-jet is set too lean it may cause starting difficulties
and poor acceleration. If the H-jet is set too lean the machine
will have less power, poor acceleration and could suffer
damage to the engine.

If both the L and H jets are set too rich it will results in
acceleration problems or too low a working speed.

Max. fast idle speed, rpm

Idle speed, rpm

365

12500

2700

372XP

13500

2700

!

WARNING! Contact your servicing dealer, if
the idle speed setting cannot be adjusted so
that the chain stops. Do not use the chain
saw until it has been properly adjusted or
repaired.

L

+ 1/4

H

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