MAINTENANCE. Husqvarna 353, 345, TS 355, 345 TAC, 346XP TAC, 353 TAC, 353 TrioBrake, 346 XP E-TECH TrioBrake

MAINTENANCE

Carburettor

Functioning, Basic setting, Final setting

WARNING! Do not start the saw without the bar, chain and clutch cover (chain brake) assembled.

If you do, the clutch might come loose and cause severe injuries.

Operation

• The carburettor governs the engine speed via the throttle. Air/fuel are mixed in the carburettor. The air/fuel mixture is adjustable. To take advantage of the saw’s maximum output the setting must be correct.

• The satisfactory operation of a catalytic converter depends, among other factors, on the correct adjustment of the carburettor. Follow carefully the instructions below, using a tachometer to check engine speed.

• Adjusting the carburettor means the engine is adapted to local operating conditions, e.g. climate, altitude, petrol and the type of

2-stroke oil used.

L H

• The carburettor has three adjustment possibilities:

L = Low speed jet.

H = High speed jet.

T = Adjustment screw for idling.

T

Conditions

• Before any adjustments are made the air filter should be clean and the cylinder cowling fitted. Adjusting the carburettor while a dirty air filter is in use will result in a leaner mixture when the filter is finally cleaned. This can give rise to serious engine damage.

• Carefully turn the L and H-jets clockwise to the bottom. Now turn the jets one turn anti-clockwise. The carburettor is now set to H =

1 and L = 1.

• Now start the saw according to the starting instructions and run it warm for 10 minutes.

NOTE! If the chain rotates the T screw should be turned anticlockwise until the chain stops.

• Place the saw 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 needle L

+ 1/4

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.

NOTE! If the chain rotates in

L the idling position, turn the idling speed screw counterclockwise until the chain stops.

• The fuel quantity required in relation to the air flow, provided by opening the throttle, is adjusted by the L and H-jets. 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 leaner mixture gives a higher engine speed and a richer mixture give a lower engine speed.

• The T screw regulates the idling speed. If the screw T is turned clockwise this gives a higher idling speed; anti-clockwise a lower idling speed.

WARNING! The catalytic converter muffler gets very hot during and after use. This also applies during idling. Be aware of the fire hazard, especially when handling the saw near flammable substances or vapours.

Final setting of the idling speed T

Adjust the idling speed with the screw T. If it is necessary to readjust, first turn the idle speed adjusting screw T clockwise, 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.

Contact your servicing dealer, if the idle speed setting cannot be adjusted so that the chain stops. Do not use the saw until it has been properly adjusted or repaired.

Basic setting and running in

The carburettor is adjusted to a basic setting when the saw is tested at the factory. The basic setting is: H = 1 turn respective L = 1 turn.

To provide the engine’s components with a good level of lubrication (running in) the carburettor should be set for a richer fuel mixture for the first 3-4 hours of operating. To obtain this adjust the speed 6-700 rpm under the recommended max.

speed.

If you do not have the possibility to check the speed using a tachometer the H-jet should not be set for a leaner mixture than that stated for the basic setting.

The recommended speed should not be exceeded.

NOTE! If the chain rotates while idling the T screw should be adjusted anti-clockwise until it stops.

Fine adjustment

• When the saw has been ”run-in” the carburettor should be finely adjusted. The fine adjustment should be carried out by

qualified person. First adjust the L-jet, then the idling screw T and then the H-jet. The following engine speed applies:

Max. speed

345: 12 500 rpm

346XP: 14 200 rpm

353: 13 000 rpm

Idling speed

2 700 rpm

2 700 rpm

2 700 rpm

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, max.

speed, etc.

High speed needle H

The high speed needle H influences the power of the saw.

A too lean adjusted high speed needle H (high speed needle H closed too much) gives overrevs and damages the engine. Let the saw run at full speed for about 10 seconds. Thereafter, turn the high speed needle H 1/

H

4 turn counter-clockwise.

Let the saw run again at full speed for about 10 seconds and note the difference of the enginesound. Repeat this procedure with the high speed needle H turned 1/4 turn more counter-clockwise. The saw has now been tested with the following settings: H=±0, H=+1/4,

H=+1/2 from basic adjustment. At full speed the engine has produced a different sound for each setting. The high speed needle

H is correctly set when the saw ”4-cycles” a little. If the saw ”whistles” the setting is too lean. If there is too much exhaust gas at the same time as the saw ”4-cycles” much, the setting is too rich. Turn the high speed needle H until the setting sounds correct.

NOTE! For optimum setting of the carburettor, contact a qualified servicing dealer who has a revolution counter at his disposal. The maximum speed recommended must not be exceeded.

Correctly adjusted carburettor

A correctly adjusted carburettor means that the saw accelerates without hesitation and the saw 4-cycles a little at max speed.

Furthermore, the chain must not rotate at idling. A too lean adjusted low speed needle L may cause starting difficulties and bad acceleration. A too lean adjusted high speed needle H gives lower power=less capacity, bad acceleration and/or damage to the engine.

A too rich adjustment of the two speed needles L and H gives acceleration problems or too low working speed.

English –

29

Starter device

WARNING!

MAINTENANCE

Tensioning the recoil spring

• When the recoil spring is assembled in the starter housing, it is in tensioned position and can when treated carelessly, pop out and cause injuries.

• Always be careful, when changing the recoil spring or the starter cord. Always wear safety goggles for eye protection.

• Lift the starter cord up in the notch on the starter pulley and turn the starter pulley 2 turns clockwise.

NOTE! Check that the starter pulley can be turned at least half a turn, when the starter cord is entirely pulled out.

Changing a broken or worn starter cord

Changing the broken recoil spring

• Loosen the screws, that hold the starter device against the crankcase and remove the starter device.

• Pull out the cord approx. 30 cm and lift it up into the notch in the pulley. Zero-set the recoil spring by letting the pulley rotate slowly backwards. Undo the screw in the centre of the pulley and remove the pulley.

• Lift the starter pulley (see

"Changing a broken or worn starter cord").

• Dissasemble the recoil spring by tapping the pully

(with its inside facing down) lightly against a working bench or similar. If the spring pops out when assembling, it should be mounted again, out and in towards the centre.

• Lubricate the recoil spring with thin oil. Assemble the starter pulley, and tension the recoil spring.

• Insert and fasten a new starter cord in the pulley.

Wind approx. 3 turns of the starter cord on to the pulley.

Assemble the starter pulley against the recoil spring, so the end of the spring engages to the pulley. Fit the screw in the centre of the pulley. Carry the starter cord through the hole in the starter housing and the starter handle. Make a knot on the starter cord.

Starter device assembly

• Assemble the starter device, by pulling the starter cord out first, then place the starter against the crankcase. Then slowly release the starter cord so that the pulley engages with the pawls.

• Assemble and tighten the screws, which hold the starter.

30

– English

Air filter

The air filter must be regularly cleaned from dust and dirt in order to avoid:

• Carburettor malfunctions

• Starting problems

• Engine power reduction

• Unnecessary wear on the engine parts

• Abnormal fuel consumption

Clean the air filter daily or more often if the air is exceptionally dusty in the working area.

• Disassemble the air filter by removing the cylinder cover and unscrew the filter.

When reassembling, make sure that the filter is tight against the filter holder.

Clean the filter by brushing or shaking it.

MAINTENANCE

Muffler

The muffler is designed in order to reduce the noise level and to direct the exhaust gases away from the operator.

The exhaust gases are hot and can contain sparks, which may cause fire if directed against dry and combustible material. Some mufflers are equipped with a special screen.

If your saw has this type of muffler, you should clean the screen at least once a week. This is done with a wire brush.

CAUTION! The screen must be replaced, if damaged. The saw will be overheated, if the screen is clogged. This results in damage on the cylinder and the piston. Never use a saw with a clogged or defective muffler.

• A more thorough cleaning of the filter is obtained by washing it in water and soap.

An air filter, which is used for some time, cannot be cleaned completely. Therefore it must be replaced by a new one, with regular intervals.

IMPORTANT! A damaged air filter must always be replaced.

A muffler fitted with a catalytic converter greatly reduces the concentration of hydrocarbons (HC), oxides of nitrogen (NO) and aldehydes emitted with exhaust gases. However, it does not cut down carbon monoxide (CO), which you cannot smell!

Consequently, never work in an enclosed or badly ventilated area. Good air circulation should always prevail when working in snowy hollows, ravines or in confined conditions.

WARNING!

The catalytic converter muffler gets very hot during and after use. This also applies during idling. Be aware of the fire hazard, especially when handling the saw near flammable substances or vapours.

A Husqvarna chain saw can be equipped with different types of airfilter according to working and weather conditions, season etc.

Spark plug Needle bearing maintenance

A

The spark plug condition is influenced by:

• An incorrect carburettor setting.

• Wrong fuel mixture (too much oil in the petrol).

• A dirty air filter.

These factors cause deposits on the spark plug electrodes, which may result in malfunction and starting difficulties.

If the engine is low on power, difficult to start or runs poorly at idling speed, always check the spark plug

first. If the spark plug is dirty, clean it and check the electrode gap. Readjust if necessary. The correct gap is

0,5 mm (0,020"). The spark plug should be replaced after about a month in operation or earlier if the electrodes are badly eroded.

IMPORTANT! Always use the recommended spark plug type. An incorrect spark plug can severely damage the piston/cylinder.

0,5 mm

The clutch drum is equipped with one of the following chain sprockets:

• Spur sprocket (A) (the chain sprocket is welded on the drum)

• Rim sprocket (B)

(exchangeable)

Both versions have built-in needle bearing at the drive shaft, whitch has to be greased regularly (once a week).

NOTE! Use only high quality bearing grease or engine oil.

B

English –

31

Adjustment of the oil pump

(346XP/353)

The oil pump is adjustable.

Adjustments are made by turning the screw using a screwdriver or combination spanner. The saw is supplied from the factory with the screw set to position 2. Turning the screw clockwise will reduce the oil flow and turning the screw anti-clockwise will increase the oil flow.

3

2

1

+

MAINTENANCE

–

WARNING! The engine must not be running when making adjustments.

Heated handles (346XPG, 353G)

On the models 346XPG and

353G both the front handle and the rear handle are equipped with electrical heating coils. These are supplied with electricity from a built-in generator in the electrical system.

When the switch is pushed upwards, the heat is switched on. When it is pushed downwards the heat is switched off.

Recommended settings:

Bar 13"-15": Position 1

Bar 15"-18": Position 2

Bar 18"-20": Position 3

Cooling system

Electrically heated carburettor

(346XPG, 353G)

This chain saw is, if it has model code XPG, equipped with electrically heated carburettor. The electrically powered heating prevents ice from forming in the carburettor. A thermostat controls the heating so that the carburettor always has the right working temperature.

To obtain the lowest possible running temperature the saw is equipped with a cooling system.

5

The cooling system consists of:

4

1.

Air intake on the starter unit.

3

2.

Air guide plate.

3.

Fan blades on the flywheel.

4.

Cooling fins on the cylinder.

2

5.

Cylinder cowling (supplies cold air over the cylinder).

1

Clean the cooling system with a brush once a week, more often in demanding conditions. A dirty or blocked cooling system

results in the saw overheating which causes damage to piston and cylinder.

NOTE! The cooling system of chain saws that are fitted with a catalytic converter must be cleaned daily. This is particularly important on saws with catalytic converters, because the higher working temperature of the exhaust demands efficient cooling of the engine and the catalytic converter unit.

Centrifugal cleaning ”Air Injection”

Centrifugal cleaning means the following:

All air to the carburettor is carried through the starter.

Dirt and dust is centrifuged away by the cooling fan.

IMPORTANT! In order to keep the function of the centrifugal cleaning, a continous maintenance and care must be made.

• Clean the air intake to the starter, the fan wings of the flywheel, the space around the flywheel, inlet pipe and carburettor space.

32

– English

Winter use

During winter time, snow and cold weather can cause running problems, such as:

• Too low engine temperature.

• Icing of the air filter and freezing of the carburettor.

Therefore some special measures are required:

• Partly reduce the air inlet of the starter and by doing that increase the engine temperature.

• Preheat the intake air to the carburettor by using the heat from the cylinder.

Temperature 0°C (32°F) or colder:

The cylinder cover is made so it can be adjusted for running in cold weather. Open the winter flap so that preheated air from the cylinder can pass into the carburettor area preventing for instance icing of the air filter.

For temperatures below -5°C

(23°F) and/or in snow conditions there is also:

• a special cover (A) for the starter housing,

• a winter plug (B) for the air intake that is fitted as shown.

These reduce the air flow and prevent large amounts of snow from being sucked into the carburettor chamber. NOTE!

When the winter plug is fitted the winter flap must be open.

IMPORTANT! If the temperature rises above -5°C (23°F) or 0°C

(32°F) respectively the saw MUST be restored to its normal settings. Otherwise there is a risk of overheating, which can cause severe engine damage.

IMPORTANT! Any maintenance other than that described in this manual must be carried out by your servicing dealer.

MAINTENANCE

Below you will find some general maintenance instructions.

If you have more questions, contact your servicing dealer.

Weekly maintenance

Daily maintenance

1.

Check the throttle trigger for smooth operation. If any binding occurs, or if engine fails to return to idle, the saw should be taken to your dealer, before it is used again.

Also, be sure that the trigger cannot be pulled until the throttle trigger lockout is depressed.

2.

Clean the chain brake and check its function according to the instructions. Make sure that the chain catcher is undamaged. Otherwise replace it immediately.

3.

Clean or replace the air filter as necessary. Check for damage or holes.

4.

The bar should be turned daily for more even wear.

Check the lubrication hole in the bar, to be sure it is not clogged. Clean the bar groove, if the bar has a sprocket tip, this should be lubricated.

5.

Check the function of the oiler to be sure the bar and chain receive proper lubrication.

6.

Sharpen the chain and check its tension and condition. Check the drive sprocket for wear.

Replace if necessary.

7.

Check the starter and starter cord for wear or damage. Clean the air intake slots on the starter housing.

8.

Check for any loose nuts and screws and retighten if necessary.

9.

Test the stop switch to be sure it shuts off the engine.

10. Check the cooling system of saw fitted with catalytic converter.

11. Make sure the mechanism for the righthand brake operates smoothly.

3

9

1

5

7

6

10

3

4

2

5

4

8

11

1

2

1.

Check that the AV elements are not soft or torn.

2.

Lubricate the clutch drum bearing.

3.

File off burrs, if any, on the sides of the bar.

4.

Clean the spark plug and check the gap.

The correct gap is 0,5 mm

(0,020 inch).

5.

Check the starter and the recoil spring. Clean the fins on the flywheel.

6.

Clean the cooling fins on the cylinder.

7.

Clean or change the screen in the muffler.

8.

Clean the carburettor body and air box.

9.

Clean the area under the cover for the right-hand brake.

Monthly maintenance

1.

Check the brake band on the chain brake for wear.

2.

Check the clutch centre, clutch drum and clutch spring for wear.

3.

Clean the outside of the carburettor.

4.

Check the fuel filter.

Change if necessary.

5.

Clean the inside of the fuel tank.

6.

Clean the inside of the oil tank.

7.

Check all cables and connections.

1

3

5

7

9

5

1

7

3

6

2

0,5 mm

4

4

2

6

8

English –

33