Husqvarna 340, 345, 346XP,350, 351, 353 manual Troubleshooting, Starting, Idling low rpm

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Troubleshooting

The various faults that can affect a chainsaw are divided into four groups. In each group the likely symp- toms are given on the left and possible causes are listed on the right. The most likely faults are given first, and so on.

Starting

Difficulty starting

Adjust L screw

 

Air filter blocked

 

Choke not working

 

Worn choke pivot

 

Worn choke valve

 

Fuel filter blocked

 

Fuel line blocked

 

Piston ring seized

 

Blocked impulse channel

 

 

Carburettor

Loose or faulty fuel pipe

leaking fuel

Hole in diaphragm

 

Worn needle valve

 

Needle valve assembly sticking

 

Needle valve set too high

 

Leak in metering system (air

 

or fuel)

 

Loose cover on carburettor

 

pump side

 

 

Flooding when

Worn needle valve

engine not

Needle valve set too high

running

Needle valve assembly sticking

 

 

Idling (low rpm)

 

 

 

Will not idle

Adjust L screw

 

Leaking air intake hose

 

(rubber)

 

Loose carburettor mounting

 

bolts

 

Loose or faulty fuel hose

 

Fuel filter blocked

 

Fuel line blocked

 

Fuel tank vent blocked

 

Throttle valve pivot stiff

 

Throttle pushrod sticking

 

Defective throttle return spring

 

Bent throttle stop

 

Faulty diffuser jet

 

 

Idling too rich

Adjust L screw

 

Worn needle valve

 

Needle valve set too high

 

Worn needle valve lever

 

Leaking control diaphragm/

 

cover plate

 

Needle valve assembly

 

sticking

 

 

Idling (low rpm) (cont.)

Idles when L

Worn needle valve

screw closed

Leaking control diaphragm/

 

cover plate

 

Needle valve assembly sticking

 

Worn needle valve lever

 

Faulty diffuser jet

 

 

Idling uneven

Fuel filter blocked

 

Fuel line blocked

 

Leaking air intake hose (rubber)

 

Loose carburettor mounting

 

bolts

 

Worn throttle valve pivot

 

Loose throttle valve screw

 

Worn throttle valve

 

Needle valve assembly

 

sticking

 

Leak in metering system (air

 

or fuel)

 

Metering system centre knob

 

is worn

 

Hole in diaphragm

 

Leaking control diaphragm/

 

cover plate

 

Crankcase leaking

 

 

L screw requires

Fuel line blocked

constant

Needle valve set too high

adjustment

Needle valve assembly sticking

 

Leak in metering system (air

 

or fuel)

 

Leaking control diaphragm/

 

cover plate

 

Faulty diffuser jets

 

Crankcase leaking

 

 

Too much fuel at

Needle valve set too high

idling

Needle valve assembly sticking

 

Metering system damaged

 

Worn needle valve

 

Leaking control diaphragm/

 

cover plate

 

Metering system incorrectly

 

assembled

 

 

10 – English

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Contents 340 345 346XP 350 351 Appendix A, Carburettor EPA models Workshop manual Husqvarna 340/345/346XP/350/351/353 ContentsConstruction and function TroubleshootingIntroduction Arrangement of the manualSpecial instructions Safety regulationsGeneral instructions Special tools 20 a 20 b 20 cTechnical data Rpm Carburettor Construction and functionConstruction and function Idling low rpm TroubleshootingStarting Acceleration and retardation High rpmChain brake dismantling Cleaning and inspectionRepair instructions Operating test Chain brake reassemblyRefit Chain catcher replacementSilencer removal Silencer refittingStop switch resistance measurement Stop switch removalChoke control removal Stop switch refittingThrottle lock, throttle trigger and return spring refitting Choke control refittingThrottle lock, throttle trigger and return spring removal Hand grip heater on model 346XPG, 351G, 353G removal Generator troubleshootingSwitch troubleshooting Troubleshooting carburettor heater 346XPG, 351G, 353G Hand grip heater on model 346XPG, 351G, 353G refitting Heater element and rear hand grip removalReplacing a broken or worn starter cord Starter assembly removalReplacing a worn recoil spring Starter assembly refittingTensioning the recoil spring Model 346XP, 351 Ignition module testingIgnition module/flywheel removal Generator refitting Replacing the generator, model 346XP, 351Ignition module and flywheel refitting Centrifugal clutch refitting Inspection and cleaningCentrifugal clutch removal Model Oil pump removal 346XP, 350, 351Oil pump -refitting 346XP, 350, 351 Oil pump removal 340Oil pump -refitting 340 Carburettor removal Adjustable oil pump adjustment 346XP, 350, 351On saws with a carburettor heater 346XPG, 351G, 353G Carburettor dismantlingCarburettor reassembly On saws with a carburettor heater 346XPG, 351G, 353G Carburettor pressure testingCarburettor refitting Carburettor heater 346XP, 351, 353 Refitting Air intake system removal Air intake system refitting Low speed jet L Carburettor adjustmentBasic requirements High speed jet H Fine adjustment of idling speed TCarburettor correct adjustment Fuel tank removalReplacing the fuel hose Replacing the fuel filterFuel tank refitting Tank vent testingIf replacing the cylinder Piston and cylinder removalModels 340 Decompression valve pressure testing Piston and cylinder refitting 346XP, 350, 351 Piston and cylinder refitting 340 Cylinder pressure testingCrankcase and crankshaft dismantling 346XP, 351 Crankshaft complete dismantling 340, 345 Crankshaft bearings replacement 346XP, 351Sealing ring replacement Sealing ring replacement drive sideTake care to avoid damaging the crank- case Crankshaft bearings 340, 345, 350 replacementCrankcase and crankshaft reassembly 346XP, 351 Crankshaft complete 340, 345, 350 reassembly Thread insert Repairing damaged threadsGuide bar bolts replacement H-needle must not rotate Basic adjustment for EPA II carburetorsReplacement of the L-needle Check that114 01 2003W12

340, 345, 346XP,350, 351, 353 specifications

Husqvarna is renowned for its high-quality chainsaws, and the Husqvarna 340, 345, 346XP, 350, 351, and 353 models are no exceptions. These models have garnered a reputation among both professional and amateur users for their reliability, durability, and cutting performance.

The Husqvarna 340 is an entry-level model designed for homeowners and light-duty tasks. It features a 40cc engine that provides a good balance of power and weight, making it easy to handle during extended use. The 340 is equipped with low-vibration technology, significantly reducing operator fatigue and making it suitable for less experienced users.

The Husqvarna 345 is slightly more powerful than the 340, boasting a 45.7cc engine. This model is ideal for users who require a bit more power for medium-duty tasks. It incorporates the air injection system, which helps to separate larger debris before it reaches the air filter, prolonging the life of the filter and maintaining optimal performance.

Moving up the range, the Husqvarna 346XP is a powerful professional chainsaw tailored for demanding tasks. With a 50.2cc engine and the X-Torq engine technology, it provides high cutting performance while reducing fuel consumption and emissions. The 346XP features an adjustable oil pump that allows for precise lubrication, making it an excellent choice for commercial users.

The Husqvarna 350 shares similarities with the 346XP but is designed for users who need a well-rounded saw for various applications. Its 50.2cc engine delivers ample power, and the ergonomically designed handle provides comfort during prolonged use. The chainsaw's advanced starting system ensures easy ignition, even in challenging conditions.

The 351 is another versatile option, equipped with a 50cc engine, designed for both professional and home use. It emphasizes user comfort and ease of handling. The compact design combined with features such as an efficient air filtration system makes the 351 suitable for long hours of work.

Lastly, the Husqvarna 353 is a heavy-duty model that excels in performance and longevity. It has a 50cc engine and incorporates various safety features, including a chain brake and throttle lock, to ensure safe operation. The saw also utilizes the unique anti-vibration system, minimizing vibrations that can lead to user fatigue.

In summary, the Husqvarna 340, 345, 346XP, 350, 351, and 353 models each offer distinct features catering to a wide range of users. From homeowners tackling light tasks to professionals requiring rugged performance, these chainsaws showcase Husqvarna's commitment to quality, innovation, and user-centric design.