Husqvarna 350 epa I, 340E EPA II, 340 EPA II manual Maintenance, General, Carburetor adjustment

Page 33

MAINTENANCE

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 carburetor 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 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 satisfactory operation of a catalytic converter depends, among other factors, on the correct adjustment of the carburetor. Carefully follow the instructions below, using a tachometer as an aid.

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

LH

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

115 09 86-95 Rev.2 2007-11-27

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

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.

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 idling 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 counter- clockwise until the chain stops. A correctly adjusted idle speed setting occurs when the engine runs smoothly in every position. It should also be good margin to the rpm when the chain starts to rotate.

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.

English 33

Image 33
Contents EPA II 340e EPA 345e EPA II 350 EPA Symbols on the machine KEY to SymbolsSymbols in the operator’s manual You will find the following labels on your chain sawEPA Contents Dear customer IntroductionWhat is what on the chain saw? What is WHAT?General Safety Precautions Before using a new chain sawAlways use common sense Machine′s safety equipment Personal protective equipmentChain brake and front hand guard General Safety Precautions Throttle lockout Chain catcherRight hand guard Cutting equipment Stop switchVibration damping system MufflerCutting equipment designed to reduce kickback BarChain General information on sharpening cutting teeth Sharpening your chain and adjusting depth gauge settingTensioning the chain 345e Lubricating cutting equipmentFilling with chain oil Checking chain lubricationChain drive sprocket Checking wear on cutting equipment Needle bearing lubricationFitting the bar and chain Assembly340, 340e 345eAssembly Fuel Fuel HandlingFueling 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 Tree felling technique Safe distanceFelling direction Felling Clearing the trunk and preparing your retreatDirectional cuts Felling cutFreeing a trapped tree Freeing a tree that has fallen badlyWhat is kickback? How to avoid kickbackGeneral advice Cutting trees and branches that are in tensionCutting the trunk into logs Maintenance Carburetor adjustmentGeneral High speed jet H Correctly adjusted carburetorImmediately Checking the brake triggerMuffler Starter Replacement of broken recoil and drive disc springsChanging a broken or worn starter cord Tensioning the recoil springSpark plug Air filterFitting the starter Drive disc spring BNeedle bearing lubrication Adjustment of the oil pump When making adjustmentsLubricating the bar tip sprocket Temperature 0C 32F or colder Air Injection centrifugal cleaningCooling system Winter useDaily maintenance Weekly maintenance Monthly maintenance Maintenance scheduleTechnical data Technical DataBar and chain combinations Saw chain filing and file gauges050 H30 058 H25 Your Warranty Rights and Obligations Federal Emission Control Warranty StatementSafety precautions for chain saw users American Standard Safety PrecautionsKickback safety precautions Other safety precautions´z+R§e¶57¨ 115 09 86-95 Rev.2 1150986-95