Husqvarna 343R, 345RX, 343F, 345FX, 345FXT Carburettor’s design, Metering unit, Blending unit

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Fuel system

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Remove the throttle cable and fuel hose from the carburettor.

Remove the carburettor.

The carburettor is made by Zama.

Design, function and servicing corre- spond with the Walbro carburettor.

Default carburettor settings:

H = 1 revolution open

L = 1 revolution open

The carburettor needles are fitted with movement limiters (caps).

The carburettor’s design

The carburettor can be divided into three different functional units: the metering unit, the blending unit, and the pump unit.

The metering unit

The needles and the fuel control functions are located here.

The blending unit

Fuel and air are mixed here.

Remove the throttle cable from the carburettor’s lever arm using flat nose pliers.

Pull off the fuel hose and remove the carburettor.

Tip!

Open the fuel cap to avoid fuel spillage caused by any excess pressure.

Attach the fuel hose to the return nipple.

The carburettor is made by Zama.

It has the same design and function as the Walbro carburettor, which means that servicing is also carried out in the same way.

The lever arm should lie flush with the carburettor housing’s contact face.

Default carburettor settings:

H = 1 revolution open

L = 1 revolution open

The carburettor needles are fitted with movement limiters (caps).

The carburettor’s design

The carburettor can be divided into three different functional units: the metering unit, the blending unit, and the pump unit.

The metering unit

The needles (A) and the fuel control functions are located here.

The needle valve (B) and control diaphragm (C) are vital to the carburet- tor’s function.

The blending unit

In this section of the carburettor fuel and air are mixed in the proper propor- tions.

The choke and throttle valves are placed here.

In the middle of the venturi (narrowest part of the throughput) the main jet (D) is found.

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Contents 343R 345RX 343F 345FX 345FXT Model 343R, 345RX, 343F, 345FX, 345FXT Contents Workshop Manual Brushcutter, TrimmerGeneral recommendations Contents Starter1Starter DismantlingAssembly StarterReplacing the drive dogs Electrical system 502 71 Electrical systemChecking the ignition spark Tip Replacing the spark Plug cover 502 50502 54 Drive dogs Heated handlesWiring diagram Electrical system Fuel system Fuel system Air filterTank venting Fuel filterDismantling Fuel pumpCarburettor Blending unit Carburettor’s designMetering unit Pump unit Dismantling the carburettorFuel system Little shorter than the L-needle PositionedFor example, the H-needle is a Assembling the carburettor H-needle is a little shorter Than the L-needleCheck carefully that the fuel hoses Are not bent or pinched whenFine adjustment Carburettor settingsBasic setting Setting Recommended max. speed must not be exceeded Correctly adjusted carburettorTachometer should always be used to find the optimal Idling speed T-screwCarburettor adjustment 345RX/FX Adjustment 345RX/FX Adjusting the L-needle Adjusting the H NeedleThrottle RotatingCheck for wear on pins a and B Tip Page Centrifugal clutch Centrifugal clutch 502 21Centrifugal clutch Do not lose the sleeve bearings found in the clutch shoesClutch drum 502 11Change the bearings in the clutch housing if necessary Page Angle gear Angle gear Let the small circlip around the axle remain503 97 Input axle with pinion must be dismantled firstShaft 503 80Cylinder and piston Cylinder and piston Decompression valve Turn the valve the right way when fittingWhen the valve is fitted the small hole must face outwards Cleaning, inspection Inlet manifoldCause Action Analysis and actionsInsufficient lubrication Piston scoring caused by heavy carbon deposits Piston damage caused by a too high engine speed Piston ring breakageForeign objects CauseService tips Defect ActionWear tolerances Crankshaft and crankcase Crankshaft and crankcase Crankshaft and crankcase 502 52Inspecting Crankshaft Assembly Leakage testing Crankcase Press down the sealing plates asFar as possible between the bolts To ensure a proper sealHusqvarna E-Tech 503 55Page Tools List of tools 502 50 502 52 503 97 502 50 505 38503 80 502 50 503 84 503 55114 01 2003W24

343R, 345RX, 343F, 345FX, 345FXT specifications

The Husqvarna 343R, 345RX, 343F, 345FX, and 345FXT are designed for efficiency and performance in demanding outdoor tasks. Each model stands out with unique features and technologies tailored to meet various needs, from professional landscaping to residential gardening.

Starting with the Husqvarna 343R, this versatile trimmer is well-known for its lightweight design and powerful performance. It is equipped with a 34 cc engine that delivers a reliable power-to-weight ratio, making it ideal for extended periods of use without excessive fatigue. The 343R features a simple start system, ensuring an easy ignition, while its Tap 'n Go trimmer head permits effortless line feeding, enhancing productivity.

Moving on to the Husqvarna 345RX, this model is favored by professionals for its robust build and advanced technology. Powered by a 45.7 cc engine, it provides superior cutting power suited for heavy-duty tasks. The 345RX comes with an ergonomic handle and a comfortable harness that allows for better weight distribution, which reduces strain during long work sessions. Additionally, the machine's X-Torq engine technology reduces fuel consumption and emissions, making it an environmentally friendly option.

The Husqvarna 343F offers a modest yet efficient powerhouse with its 34 cc engine. It is user-friendly, making it an excellent choice for recreational users or those new to outdoor maintenance. This model features an adjustable handle to accommodate various cutting angles, enhancing versatility according to the user's preference.

Next is the Husqvarna 345FX, an exceptional tool for professional use, boasting a high-performing 45.7 cc engine. The 345FX incorporates advanced vibration dampening technology, resulting in reduced operator fatigue during lengthy operations. Its advanced cutting attachments provide versatility for tackling different vegetation types, enhancing user experience.

Finally, the Husqvarna 345FXT merges performance with functionality. Like the 345FX, it features a 45.7 cc engine with exceptional power, but comes with additional features such as an easy-to-adjust harness and advanced cutting heads. This model is particularly suited for demanding tasks, offering extended run time and increased efficiency.

In summary, Husqvarna’s 343R, 345RX, 343F, 345FX, and 345FXT trimmers are engineered with cutting-edge technologies. Each offers unique features that cater to the distinct needs of both casual users and professionals. These models ensure optimal performance, efficiency, and comfort, making them excellent choices for various outdoor maintenance tasks.
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