Husqvarna Expert Maintenance Tips for Chainsaws 343FR and 345RX

Page 27

MAINTENANCE

Carburetor

Your Husqvarna product has been designed and manufactured to specifications that reduce harmful emissions. After the engine has used 8-10 tanks of fuel the engine will be run-in.To ensure that it continues to run at peak performance and to minimise harmful exhaust emissions after the running-in period, ask your dealer/service workshop (who will have a rev counter at their disposal) to adjust your carburettor.

WARNING! The complete clutch cover and

!shaft must be fitted before the machine is started, otherwise the clutch can come loose and cause personal injury.

Carburetor adjustment

The carburettor can be designed in different ways, depending on the existing environmental and emissions legislation. Some machines are equipped with movement limiters on the carburettor’s adjuster screws. These limit the adjustment range to a maximum of 1/2 turn.

1/2

1/2

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

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 setting

The basic carburetor settings are adjusted during testing at the factory. The basic setting is richer than the optimal setting and should be maintained for the first few hours the machine is in use. The carburettor should then be finely adjusted. Fine adjustment should be carried out by a skilled technician.

CAUTION! If the cutting attachment rotates when the engine is idling the idle adjustment screw T should be turned anti- clockwise until the cutting attachment stops.

Rec. idle speed 2700 rpm

Recommended max. speed: See the Technical data section.

WARNING! If the idle speed cannot be

!adjusted so that the cutting attachment stops, contact your dealer/service workshop. Do not use the machine until it has been correctly 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, make sure that the air filter is clean and the air filter cover is fitted. If you adjust the carburettor when the air filter is dirty it will result in a leaner mixture when the filter is finally cleaned. This can lead to serious engine damage.

Carefully turn both jets, L and H, so that they are midway between fully screwed in and fully screwed out.

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 cutting attachment rotates when the engine is idling the idle adjustment screw T should be turned anti-clockwise until the cutting attachment stops.

Low speed jet L

Try to find the highest idling speed, turning the low speed needle L clockwise respectively counter-clockwise. When the highest speed has been found, turn the low speed needle L 1/ 4 turn counter-clockwise.

CAUTION! If the cutting attachment rotates when the engine is idling the idle adjustment screw T should be turned anti- clockwise until the cutting attachment stops.

English – 27

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Contents English 343F 345FX 345FXT 343FR 343R 345RXSymbols KEY to SymbolsContents Dear customer IntroductionWhat is what on the clearing saw? 343R, 345RX What is WHAT?What is what on the clearing saw? 343F, 345FX, 345FXT What is what on the clearing saw? 343FR Personal protective equipment General Safety PrecautionsMachine′s safety equipment Stop switchThrottle lockout Muffler Cutting attachment guardVibration damping system Quick releaseLocking screw Locking nutCutting equipment Cutting equipmentSharpening grass cutters and grass blades Trimmer head Sharpening the saw bladeAssembly Assembling the handlebar and throttleTransport position, handlebar Assembling the cutting equipment Fitting the blade guard and saw blade 343F, 345FX, 345FXT343FR, 343R, 345RX Adjusting the harness and clearing saw Fitting other guards and cutting attachmentsStandard harness Adjusting the harness Triobalance harnessCorrect balance Fuel safety Fuel HandlingFuel Mixing FuelingCold engine Starting and StoppingCheck before starting Starting and stoppingStarting StoppingHeated handles ABC of clearing Basic safety rulesWorking Techniques General working instructionsWorking methods Forestry clearing using a saw bladeBrush cutting with a saw blade Grass clearing using a grass bladeTrimming Grass trimming with a trimmer headCarburetor MaintenanceHigh speed jet H Fine adjustment of the idle speed TCorrectly adjusted carburetor Adjusting the start throttle speed 343FR, 343R, 345RXAir filter Cleaning the air filterMuffler Cooling systemWinter use Bevel gearDrive shaft Spark plugTemperature 0C 32F or colder Maintenance Daily Weekly Monthly Maintenance scheduleTechnical data Technical Data345FX 345FXT Engine 343FR Centre hole in blades/cutters, Ø 25,4 mm Technical Data Your Warranty Rights and Obligations Federal Emission Control Warranty StatementPage 095-.130 ~ 3,5 mClic 35-50 NM Page Mm 9,0 m Mm 7,5 m Mm 6,0 m 15 cm 10 m 10 cm 15 cm Clic 1150276-95 ´z+Re¶5p¨ ´z+Re¶5p¨