Husqvarna Complete Guide to 346 XPG: Repair and Maintenance Manual
Page 43

Repair instructions

8

When replacing the cylinder 340, 345: Unscrew the decompression valve. (345) Remove the intake system, see “Air intake system

– removal”.

Model 350 is fitted with a spacer, which is secured using four bolts from the underside. The spacer does not however need to be removed when removing the cylinder.

Cleaning and inspection

Clean all the components, scraping off all traces of old gasket and carbon from the following places:

•Piston crown

•Top of the cylinder bore

•Cylinder exhaust port

•Decompression valve channel (340, 346XP, 350, 351, 353)

•Cylinder base and/or crankcase

Check the following:

•The surface coating of the cylinder is not worn through, especially in the upper part of the cylinder.

•The cylinder is free from score marks and areas of wear.

•The piston is free from score marks. Small scratches can be polished out with fine emery paper.

•The piston ring is not burnt into its groove.

•Measure piston ring wear. This should not exceed 1 mm. Use the piston to push down the piston ring.

•The needle roller bearing is undamaged.

•The inlet manifold is undamaged.

•Pressure test the decompression valve.

•Also refer to Jonsered’s Analysis guide for piston failures, art. no. 108 07 01-01.

Decompression valve – pressure testing

1

Connect tool 502 50 38-01 to the decompression valve.

2

Pump up the pressure to 80 kPa (0.8 bar).

3

Wait 30 seconds.

4

The pressure should not be less than 60 kPa (0.6 bar).

42 – English

Page 42 Page 44
Image 43
Page 42 Page 44
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 manualGeneral instructions Safety regulationsSpecial instructions Special tools 20 a 20 b 20 cTechnical data Rpm Carburettor Construction and functionConstruction and function Starting TroubleshootingIdling low rpm Acceleration and retardation High rpmRepair instructions Cleaning and inspectionChain brake dismantling 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 removal Choke control refittingThrottle lock, throttle trigger and return spring refitting Switch troubleshooting Generator troubleshootingHand grip heater on model 346XPG, 351G, 353G removal 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 removalTensioning the recoil spring Starter assembly refittingReplacing a worn recoil spring Ignition module/flywheel removal Ignition module testingModel 346XP, 351 Generator refitting Replacing the generator, model 346XP, 351Ignition module and flywheel refitting Centrifugal clutch removal Inspection and cleaningCentrifugal clutch refitting 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 Carburettor refitting Carburettor pressure testingOn saws with a carburettor heater 346XPG, 351G, 353G Carburettor heater 346XP, 351, 353 Refitting Air intake system removal Air intake system refitting Basic requirements Carburettor adjustmentLow speed jet L 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 testingModels 340 Piston and cylinder removalIf replacing the cylinder 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 sideCrankcase and crankshaft reassembly 346XP, 351 Crankshaft bearings 340, 345, 350 replacementTake care to avoid damaging the crank- case Crankshaft complete 340, 345, 350 reassembly Guide bar bolts replacement Repairing damaged threadsThread insert 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.
Top Page Image Contents