Maintenance; General; Carburetor Adjustment - Husqvarna 385XP Operator's Manual

General

The user must only carry out the maintenance and
service work described in this manual.
IMPORTANT! Any maintenance other than that
described in this manual must be carried out by your
servicing dealer (retailer).

Carburetor adjustment

Due to existing environmental and emissions legislation
your chain saw is equipped with movement limiters on the
carburettor adjuster screws. These limit the adjustment
possibilities to a maximum of a 1/2 turn.
Your Husqvarna product has been designed and
manufactured to specifications that reduce harmful
emissions.
Function, Basic settings, Fine adjustment
WARNING! Do not start the chain saw
!
unless the bar, chain and clutch cover
(chain brake) are fitted, otherwise the
clutch may come loose and cause
personal injury.
Function
• The carburetor governs the engine's speed via the
throttle control. Air and fuel are mixed in the
carburetor. The air/fuel mixture is adjustable. Correct
adjustment is essential to get the best performance
from the machine.
• The setting of the carburetor means that the engine is
adapted to local conditions, for example, the climate,
altitude, fuel and the type of 2-stroke oil.
• The carburetor has three adjustment controls:
- L = Low speed jet
- H = High speed jet
- T = Idle adjustment screw
T
L
30 – English

MAINTENANCE

1/2
1/2
H
• 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. Avoid running at a too high speed for
extended periods during the first 10 hours.
CAUTION! If the chain rotates while idling the T-screw
must be turned anti-clockwise until the chain stops.
Rec. idle speed: 2700 rpm
WARNING! Contact your servicing
!
dealer, if the idle speed setting cannot be
adjusted so that the chain stops at idle.
Do not use the chain saw until it has
been properly adjusted or repaired.
Fine adjustment
When the machine has been "run-in" the carburetor
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.
Conditions
• Before any adjustments are made the air filter should
be clean and the cylinder cover fitted. Adjusting the
carburetor 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.
• Do not attempt to adjust the L and H jets beyond
either stop as this could cause damage.
• 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
Turn the low speed jet L clockwise until it stops. If the
engine accelerates poorly or idles unevenly, turn the low
speed jet L anticlockwise until good acceleration and
idling are achieved.
CAUTION! If the chain rotates while idling the T-screw
must be turned anti-clockwise until the chain stops.