Husqvarna 570 576 XP manual Maintenance, General, Carburettor adjustment

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MAINTENANCE

General

The user must only carry out the maintenance and service work described in this Operator’s Manual. More extensive work must be carried out by an authorised service workshop.

Carburettor 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.

1/2

1/2

Your Husqvarna product has been designed and manufactured to specifications that reduce harmful emissions.

Function

The carburettor governs the engine’s speed via the throttle control. Air and fuel are mixed in the carburettor. The air/fuel mixture is adjustable. Correct adjustment is essential to get the best performance from the machine.

Adjusting the carburettor means that the engine is adapted to local operating conditions, e.g. climate, altitude, petrol and the type of 2-stroke oil.

The carburettor has three adjustment controls:

-L = Low speed jet

-H = High speed jet

-T = Idle adjustment screw

L H

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 carburettor settings are adjusted during testing at the factory. Avoid running at a too high speed 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

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.

Changing the type of fuel

Fine tuning may be required if the chain saw, after changing the type of fuel, performs differently with regard to starting, acceleration, maximum speed, etc.

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.

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.

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.

Fine adjustment of the idle speed T

Adjust the idle speed with the T-screw. If it is necessary to re-adjust, turn the T-screw clockwise while the engine is running, until the chain starts to rotate. Then turn anti- clockwise until the chain stops. 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 chain starts to rotate.

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.

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Contents 570 576 XP Symbols in the operator’s manual KEY to SymbolsSymbols on the machine Contents Dear Customer IntroductionWhat is what on the chain saw? What is WHAT?Before using a new chain saw General Safety PrecautionsAlways use common sense Machine′s safety equipmentPersonal protective equipment Chain brake and front hand guardGeneral Safety Precautions Right hand guard Throttle lockoutChain catcher Cutting equipment Stop switchVibration damping system MufflerBar Cutting equipment designed to reduce kickbackChain Injuries Some terms that describe the bar and chainGeneral information on sharpening cutting teeth Sharpening your chain and adjusting depth gauge settingTensioning the chain Which could lead to serious, even fatal injuries Chain oil Lubricating cutting equipmentFilling with chain oil Checking chain lubricationChecking wear on cutting equipment Chain drive sprocketNeedle bearing lubrication Fitting the bar and chain AssemblyFitting a spike bumper Working with the chainFuel Fuel HandlingFuelling Fuel safetyTransport and storage Long-term storageStarting and stopping Starting and StoppingCold engine Warm engineStopping Working Techniques Basic safety rulesBefore use General working instructionsGeneral rules Terms Basic cutting techniqueLimbing Safe distance Tree felling techniqueFelling direction Clearing the trunk and preparing your retreatFelling cut Directional cutsCutting trees and branches that are in tension Freeing a tree that has fallen badlyFreeing a trapped tree What is kickback? How to avoid kickbackGeneral advice Cutting the trunk into logsGeneral MaintenanceCarburettor adjustment High speed jet H Correctly adjusted carburettorChecking brake band wear Checking the front hand guardImmediately Checking the inertia brake releaseMuffler Changing a broken or worn starter cord StarterTensioning the recoil spring Changing a broken recoil springLubricating the bar tip sprocket Air filterSpark plug Air Injection centrifugal cleaning Adjustment of the oil pumpRunning when making adjustments Needle bearing lubricationHeated handles Winter useDaily maintenance Weekly maintenance Monthly maintenance Maintenance scheduleTechnical data Technical DataSaw chain filing and file gauges EC-declaration of conformity Bar and chain combinationsApplies to Europe only EN ISO 12100-22003, Cispr 122001, EN ISOPage Page ´z+SÆ6¶6w¨ Page 1151002-26