Husqvarna 340, 345, 346XP,350, 351, 353 manual Basic adjustment for EPA II carburetors, Check that

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Repair instructions

Appendix A

Basic adjustment for EPA II carburetors

After replacing the carburetor or high speed and/or low speed needle on an EPA (The US Environmental Protection Agency) certified product a basic adjustment must be carried out as described below in order to meet the EPA-requirements. This to achieve as low emissions as possible. This instruction is made for USA & Canada only. On EPA carburetors both the H- and L-needles are fitted with caps to prevent the chain saw operator from changing the adjustment above EPA standard. The caps can be removed to achieve richer or leaner adjustments. To set the needles correctly an adjustment sleeve is fitted from the factory over the caps to lock them in maximum allowed settings.

When correctly set the caps must be fixed on the nee- dles. The adjustment sleeve then can be removed. Over the caps on complete sparepart carburetor, there is a plastic sleeve which is intended to lock the caps at the richest position (anticlockwise towards stop) during the time that the needles are adjusted. When the adjustment is complete and the caps have been fixed on the nee- dles, the sleeve is no longer of any function and can be removed.

NOTE! On the complete spare part carburetor, the L- needle is adjusted from the factory.

NOTE! Before making any adjustments the following must be done!

•Mount, for this model, approved bar & chain combina- tion (See Technical data in the Operator’s manual).

Model

340/345/350 16”

346XP/35116”

•The chain should not be tensioned more than that it remains ~0,2 inches to the bar.

•Mount a new air filter.

Replacement of the H-needle or complete carburetor

1.Screw the new H-needle to the bottom and turn it counterclockwise ”A” turns.

Model

 

340/345/350

A = 3/4

346XP/351

A = 3/4

2.Check that:

The H-cap is adjusted to its richest setting. (Turned counterclockwise to stop). The cap is not fixed to the needle, it should rotate independently. Adjust the L-cap to a center position (1/4 turn counterclockwise = minimum, 1/4 turn clockwise = maximum).

3.Start the engine. If necessary, adjust the idling speed with the T-screw until the chain stops.

4.Adjust the H-needle to give a top speed of ”B” rpm.

Model

 

340/345/350/351

B = 12 000

346XP

B = 13 000

Use a narrow blade screwdriver (Ref.no. 531 00 48-63) and insert it through the hole in the cap (max. blade width 2 mm/0.08 inch).

5.Let the engine run at ”B” rpm ~ 1 minute, until warm.

6.Adjust the H-needle to a top speed of ”C” rpm.

Model

 

340/345/350/351

C = 13 700

346XP

C = 14 300

7.Check that the H-cap is still adjusted to its richest setting. (Turned counterclockwise to stop). NOTE!

The H-needle must not rotate!

8.Gently knock the H-cap into position. Use a 5 mm/0.2 inch mandrel (for ex. the locking pin for the bevel gear ref.no. 502 02 61-03). This is a basic carburetor adjustment. Further fine adjustments, within the limits the caps allow, may be necessary to achieve optimum performance. See the Operator’s manual.

Replacement of the L-needle

1.Take off the cap from the L-needle using e.g. a pair of cutting pliers and unscrew the needle.

2.Screw the new L-needle to the bottom and then turn it counterclockwise ”D” turns.

Model

 

340/345/350

D = 1 1/2

346XP/351

D = 1 1/2

3.Press a new L-cap on the L-needle to the first stop, which means that the cap is not fixed to the needle, it should rotate independently.

4.Adjust the L-cap to the richest position (turned counterclockwise to stop) without turning the needle.

5.Let the engine run at ~ ”E” app.1 minute until warm and then let it run on idle.

Model

 

340/345/350/351

E = 12 000

346XP

E = 13 000

6. Adjust the idle speed to ”F” rpm.

Model

 

340/345/350

F = 2 700

346XP/351

F = 2 700

7.Adjust the L- needle until the highest possible idling speed is achieved and then turn the

L-needle 1/2 turn counterclockwise. Use a narrow blade screwdriver w. ref.no. 531 00 48-63 and insert through the hole in the cap (max. blade width 2 mm/ 0.08 inch) .

NOTE! If the chain rotates, turn the idling speed screw (T) counterclockwise until the chain stops.

8.Check that the L-cap is still adjusted to its richest position. (Turned counterclockwise to stop).

NOTE! The L-needle must not rotate!

9.Gently knock the L-cap into position. Use a 5 mm/0.2 inch mandrel (for ex. the locking pin for the bevel gear ref.no. 502 02 61-03).

This is a basic carburetor adjustment. Further fine adjustments, within the limits the caps allow, may be necessary to achieve optimum performance. See the Operator’s manual.

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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 manualSafety regulations General instructionsSpecial instructions Special tools 20 a 20 b 20 cTechnical data Rpm Carburettor Construction and functionConstruction and function Troubleshooting StartingIdling low rpm Acceleration and retardation High rpmCleaning and inspection Repair instructionsChain brake dismantling Operating test Chain brake reassemblyRefit Chain catcher replacementSilencer removal Silencer refittingStop switch resistance measurement Stop switch removalChoke control removal Stop switch refittingChoke control refitting Throttle lock, throttle trigger and return spring removalThrottle lock, throttle trigger and return spring refitting Generator troubleshooting Switch 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 removalStarter assembly refitting Tensioning the recoil springReplacing a worn recoil spring Ignition module testing Ignition module/flywheel removalModel 346XP, 351 Generator refitting Replacing the generator, model 346XP, 351Ignition module and flywheel refitting Inspection and cleaning Centrifugal clutch removalCentrifugal 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 pressure testing Carburettor refittingOn saws with a carburettor heater 346XPG, 351G, 353G Carburettor heater 346XP, 351, 353 Refitting Air intake system removal Air intake system refitting Carburettor adjustment Basic requirementsLow 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 testingPiston and cylinder removal Models 340If 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 sideCrankshaft bearings 340, 345, 350 replacement Crankcase and crankshaft reassembly 346XP, 351Take care to avoid damaging the crank- case Crankshaft complete 340, 345, 350 reassembly Repairing damaged threads Guide bar bolts replacementThread 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.
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