High Speed Jet H; Correctly Adjusted Carburettor; Checking, Maintaining And Servicing Chain Saw Safety Equipment - Husqvarna 439 Manual De Instrucciones

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.

High speed jet H

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 jet.
CAUTION! If the high speed jet is screwed in too far,
it may damage the piston/cylinder.
When test run at the factory, the high speed jet is set so
that the engine satisfies the applicable legal requirements
at the same time as achieving maximum performance.
The carburettor's high speed jet is then locked using a
limiter cap in the fully screwed out position. The limiter cap
limits the potential to adjust the high speed jet to at most
half a turn.

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.
MAINTENANCE
Checking, maintaining and
servicing chain saw safety
equipment
Note! All service and repair work on the machine
demands special training. This is especially true of the
machine's safety equipment. If your machine fails any of
the checks described below we recommend that you
take it to your service workshop.
Chain brake and front hand guard
Checking brake band wear
• Brush off any wood dust, resin and dirt from the chain
brake and clutch drum. Dirt and wear can impair
operation of the brake.
• Regularly check that the brake band is at least 0,6 mm
thick at its thinnest point.
Checking the front hand guard
• Make sure the front hand guard is not damaged and
that there are no visible defects such as cracks.
• Move the front hand guard forwards and back to make
sure it moves freely and that it is securely anchored to
the clutch cover.
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