HUSQVARNA 350 Service Manual

Before you begin inspection and maintenance, ensure that the unit is on a stable, level surface and is fully cooled if it has been running recently. Remove the spark plug boot to prevent any accidental starting, and disconnect the battery if applicable to the model variant. Inspect the surroundings for any fuel leaks or spilled oil, and prepare a clean workspace with ample lighting and the necessary tools. Gather the owner’s manual, service manual, and any OEM replacement parts recommended for the Husqvarna 350 to ensure compatibility and proper specifications. Verify that you have a clear plan for the procedure you intend to execute, and confirm that you have adequate ventilation if you will be working with fuel or solvents. Maintain a clean area free of clutter to reduce the risk of dropping small fasteners or losing critical components inside the machine.

Personal protective equipment and safe work practices are essential for reducing the risk of injury during inspection and maintenance. Wear cut-resistant gloves when handling sharp components, and use eye protection to guard against debris or chemical splashes. A snug-fitting long-sleeve shirt and sturdy, non-slip footwear help minimize skin exposure and improve stability while positioning tools. When handling fuel or solvents, work in a well-ventilated area and keep a spill containment plan ready, including absorbent materials and a suitable container for disposing of waste. Use a torque wrench or calibrated drivers for fasteners that require precise tightening to avoid overtightening or under-tightening, which can lead to component damage or performance issues. After finishing, perform a brief functional check in a controlled manner, ensuring that all safety features operate correctly and that no tools or rags are left in or around the cooling fins, exhaust, or air intake paths.

The Husqvarna 350 chainsaw is designed for professional forestry and demanding cutting tasks, combining rugged construction with efficient performance. Key components include the engine housing, anti-vibration system, guide bar and chain assembly, fuel and oil tanks, and the automatic carburetor oiler. The top-handled layout emphasizes maneuverability and balance, allowing operators to maintain precise control during prolonged use. A robust front handle and rear grip provide secure handling, while the chain brake, throttle lock, and safety chain tensioning system contribute to safe operation in varying conditions. Regular maintenance access points, such as the air filter cover and spark plug area, are positioned to minimize downtime and keep the unit ready for demanding work shifts.

In operation, the combination of a two-stroke engine, electronic ignition, and a lightweight yet durable chassis delivers reliable power with a favorable power-to-weight ratio. The anti-vibration system reduces operator fatigue, which is essential during extended felling or bucking sessions. The automatic oiler ensures consistent chain lubrication, extending chain life and improving cutting efficiency. The saw is equipped with a chain catcher and a sturdy housing to protect the operator from kickback and debris. Understanding the interaction of these components helps technicians diagnose performance issues more efficiently and plan preventative maintenance around typical wear patterns.

Specifications and rating information for the Husqvarna 350 reflect its intended professional use and performance envelope. Displacement, bore, and stroke determine the engine’s breathing characteristics, while the compression ratio influences starting reliability and torque delivery. The carburetion system, combined with the ignition timing, governs fuel efficiency and power output across a range of operating temperatures. The chain speed, bar length compatibility, and chain pitch are selected to balance cutting aggressiveness with control, ensuring safe operation on a variety of wood densities. The weight, fuel capacity, oil capacity, and overall dimensions are crucial data points for planning transport, service intervals, and ergonomic setup for different operators and job sites.

Maintenance intervals are closely tied to these specifications, with routine checks on the air filter, fuel and oil lines, spark plug, and cooling passages. Proper tensioning of the drive sprocket and guide bar ensures even chain wear and reduces the risk of derailment during aggressive cuts. The lubrication system’s performance should be verified by inspecting the oil flow and chain lubrication lines, especially after exposure to dust or timber resins which can clog passages. Operators should record service milestones, including filter replacements, chain sharpening, and fuel system inspections, to maintain compliance with safety and warranty requirements as outlined by the manufacturer. A thorough understanding of the machine’s components and specifications enables technicians to perform precise diagnostics and execute effective repairs while maintaining optimal performance.

Prestart checks and setup

Before operating any outdoor power equipment, it is essential to perform thorough prestart checks to ensure safe and reliable performance. Begin with a visual inspection of the Husqvarna 350, looking for any obvious damage, loose fasteners, or signs of wear on critical components such as the fuel line, air filter, and spark plug boot. Check the fuel system for cracks, leaks, or degraded hoses, and verify that the battery (if equipped) is securely connected and charged. Ensure that the chain brake, throttle lock, and stop switch function properly, and confirm that the chain is correctly tensioned according to the manufacturer's specifications. A clean, unobstructed work environment reduces the risk of injury and helps identify issues more easily during the check. Examine the exhaust area for any unusual buildup or signs of overheating, and ensure that there are no fuel spills or fumes that could compromise safety during startup.

Fuel system inspection and preparation is a critical step in readying the saw for operation. Use clean, fresh gasoline appropriate for two-stroke engines and mix with the correct ratio if a premix is required; never use old or contaminated fuel. Inspect the fuel filter for blockages and replace it if needed to maintain proper fuel flow. Confirm that the fuel tank cap vent is clear to prevent vacuum formation, which can hinder fuel delivery. Verify that all quick-connect fuel lines are securely attached and free of cracks, and ensure that the primer bulb (if present) operates smoothly without signs of degradation. Proper fuel preparation reduces starting effort and helps prevent engine damage due to lean or rich mixtures.

Lubrication and cooling system checks are crucial for consistent performance and longevity. Ensure the bar and chain oil reservoir is filled to the specified level with the recommended lubricant, and confirm the delivery system operates when the saw is running. Check the chain tension and lubrication path to verify that oil reaches the chain properly, which minimizes wear and overheating. Inspect the cooling fins and air intake for obstructions such as dust or debris; clear any blockages to maintain adequate airflow and prevent overheating during operation. Verify that the air filter is clean and properly seated, as a clogged filter can cause excessive engine wear and reduced performance. A well-lubed and properly cooled engine runs cooler, produces steadier power, and extends the service life of internal components.

Warming up and idle procedures set the stage for a safe and controlled startup. Start with a cold engine on a stable surface, following the manufacturer’s recommended starting sequence to avoid abrupt throttle movement. Allow the engine to idle briefly after starting to reach normal operating temperature, listening for any abnormal noises, knocking, or exhaust smoke that might indicate a mechanical issue. Gradually apply throttle to bring the engine into a light work state and monitor for smooth acceleration and stable idle speed. During warm-up, ensure the chain brake is engaged and the chain is stationary to prevent accidental contact. If the engine exhibits hesitation, misfire, or unusual vibrations, stop the test and recheck fuel, air, and spark components before proceeding with any heavy operation.

Maintenance schedule and intervals

The maintenance schedule for the Husqvarna 350 is designed to ensure reliable operation and optimal performance across varying workloads. Establishing a consistent cadence for inspections, adjustments, and part replacements helps prevent unexpected failures and extends the life of the equipment. Begin with a thorough review of the owner's manual to confirm specific torque values and service intervals, as these can vary with model year and regional regulations. Create a maintenance log that records dates, operating hours, performed tasks, and any parts replacement to track wear trends over time. This record will be valuable for diagnosing intermittent issues and planning preventive actions ahead of time.

Routine maintenance should be performed on a regular basis, regardless of usage intensity. Visual inspections for loose fasteners, worn cables, and cracked hoses should be conducted before each use. Check the air filter, fuel filter, and spark plug for signs of dirt, damage, or wear, and replace or clean as needed. Inspect the cooling fins and surrounding components to ensure unobstructed airflow, particularly after operation in dusty environments or high-temperature conditions. Keep the user manual’s torque specifications handy when performing reassembly tasks to avoid overtightening or insufficient clamping force. A disciplined approach to routine checks minimizes the risk of component failure during operation and contributes to safer, more efficient performance.

Seasonal maintenance practices address longer-term wear and environmental exposure. At the start of the season, perform a comprehensive inspection of the drive system, including the clutch and sprockets, and replace worn components to maintain proper power transfer. Conduct a full carburetor inspection and consider a rebuild if the unit demonstrates hard starting, poor idle stability, or inconsistent fuel delivery. Replace fuel lines if they show signs of cracking or swelling, and refresh the ethanol-containing fuel system with appropriate cleaners if recommended by Husqvarna service guidelines. During storage periods, empty or stabilize fuel as advised and clean all external surfaces to prevent corrosion. Seasonal tasks also include checking the oiling system for signs of leaks or reduced flow, ensuring the bar and chain are properly tensioned and lubricated, and confirming that the chain brake and safety features operate correctly. Maintaining discipline with seasonal tasks helps ensure reliability and safety when the equipment is needed most.

Guided disassembly sequence: Begin by ensuring the power is removed and the unit is stabilized on a clean, level bench with ample lighting. Gather the necessary tools and organize fasteners by type and size to preserve the original assembly order. Carefully remove exterior covers starting with the most accessible panels, keeping track of any vibration dampers or shielding that may affect reassembly. As components are exposed, document their condition with notes or photos to aid subsequent inspection, and label wiring or hoses to prevent misrouting. When removing the bar/chain brake and tensioning components, apply controlled pressure and retain all springs, pins, and quick-release mechanisms in a safe location to avoid loss. Proceed to disconnect the fuel lines, carburetor linkage, and exhaust components only after verifying that fuel is drained and the engine is cool to prevent accidental spills or injury. Maintain a clean work surface and replace any gaskets or seals only after confirming that mating surfaces are free of debris and damage. Throughout the process, reference the service manual diagrams to confirm the correct orientation of parts and the appropriate sequence for reassembly, ensuring that all fasteners are torqued to the specified values in the final check.

Wear inspection and part evaluation: With the major assemblies exposed, inspect the wear items for signs of fatigue, scoring, or deformation. Pay particular attention to the piston rings, cylinder walls, and crankshaft seals, as excessive wear can indicate improper lubrication or contamination. Examine the clutch and drive system for glazing, missing springs, or worn shoes, which can impair performance and reliability. Inspect the bar and chain for bar nose wear, chain stretch, and drive sprocket wear, replacing components that exceed service limits to prevent kickback or unstable operation. Inspect the air filtration system for clogged media or cracks in the housing, and assess the carburetor for varnish buildup, ensuring proper idle and throttle response after any cleaning. Check all seals and gaskets for hardening or cracks, replacing them as necessary to preserve compression and fuel integrity. Finally, test electrical connections, switchgear, and the ignition system for continuity and proper grounding, addressing corrosion or loose connectors before reassembly to avoid intermittent faults after startup.

Repair and component replacement

The Husqvarna 350 chainsaw is designed with durable components that endure demanding outdoor use, but routine maintenance and timely replacement of wear parts are essential to maintain performance and safety. Begin by inspecting the air intake system, including the air filter, housing, and pre-cleaner, as part of every service interval. A clogged filter restricts airflow, reduces engine efficiency, and increases fuel consumption, so replace the filter if it shows excessive dirt or damage. When removing or installing components, ensure the saw is cool, the spark plug is disconnected, and the chain brake is engaged to prevent accidental movement. Use manufacturer-approved replacement parts to preserve the calibration and reliability of the carburetor, clutch, and ignition systems. Document any unusual wear or damage observed during inspection to support preventive maintenance planning and future repairs.

Common wear parts and replacement guidance involves a structured assessment of items that typically degrade with use. The chain, cutting sprocket, and guide bar experience elongation, burrs, and pitch wear that can affect cutting efficiency and safety; inspect for bend or crack marks and replace when indicated. The fuel and impulse lines, as well as the carburetor diaphragms, should be checked for cracks or hardening, which can cause starting difficulties or unstable idle. The air filter, spark plug, and muffler components should be evaluated for buildup or carbonization, and cleaning or replacement performed according to service intervals. Retaining fasteners, drive gears, and the recoil starter assembly should be examined for wear, with any looseness or deformation corrected by proper torquing and part replacement. Maintaining an organized workspace and using a parts diagram can help ensure the correct sequence and placement during reassembly, reducing the risk of misfit components and downtime.

Bearing and seal replacement procedures require careful disassembly to avoid damaging the crankshaft, housings, or seals. Before removing bearings, clean any debris from the exterior and verify that the saw is fully discharged of fuel and oil; this prevents contamination and safety risks. Access typically involves removing the protective shrouds, flywheel, and side cover, followed by the precise extraction of bearings using appropriate pullers or press tools, ensuring the inner races remain undamaged. When installing new bearings or seals, apply a light coat of compatible lubricant to the inner race and fit the parts with even pressure to avoid creating race flats or misalignment. After installation, verify smooth rotation by hand and listen for any grinding or rough spots, which would indicate improper seating. Reassemble the saw with attention to torques specified by the manufacturer and perform a test run at a safe, controlled speed to confirm that the bearing and seal replacements restore normal operation without leaks or abnormal noise.

For both sections, maintaining proper alignment and cleanliness throughout the process is critical. Use a labeled tray or magnetic mat to keep fasteners organized, and replace any gaskets or seals that appear degraded to prevent leaks. Always wear personal protective equipment and follow local disposal guidelines for old filters, oil, and damaged parts. Document the maintenance work with dates, part numbers, and observed conditions to support warranty requirements and future maintenance planning. If a repair exceeds the recommended skill level or requires specialized tools, consult a certified service technician to avoid compromising safety or performance.

Fuel system cleaning and contributions: The fuel system of the Husqvarna 350 relies on clean, consistent fuel delivery to maintain optimal performance and engine longevity. Start by inspecting the fuel tank for signs of contamination, such as rust, sediment, or thin varnish that can pass through the fuel line. Remove the fuel cap and vent lines to ensure there are no blockages that could create a vacuum or pressure imbalance during operation. When preparing to clean, disconnect the spark plug boot for safety and relieve any residual pressure in the line by loosening the fuel line fitting at the carburetor with the engine off. Use a spray carburetor cleaner to dissolve gum and varnish within the fuel jet passages and lines, while being careful not to soak diaphragms or gaskets, which can cause swelling or deterioration. After cleaning, reinstall all components securely and replace the fuel filter if equipped, as a clogged filter will reduce fuel flow and affect carburetion. Finally, use fresh, high-quality unleaded fuel mixed with the correct oil ratio as specified by the manufacturer, and adopt a minimum storage practice of stabilizing agents to prevent fuel degradation during idle periods.

Carburetor adjustment and tuning procedures: The carburetor on the Husqvarna 350 must be adjusted to compensate for altitude, temperature, and fuel quality to achieve stable idle and reliable acceleration. Begin with the base settings recommended by Husqvarna for the model, noting the initial screw positions for reference. Idle speed should be set to a steady, low RPM with the engine warm, ensuring that the chain brake engages properly and the saw does not creep when idling. If the engine stalls or bogs down under light throttle, carefully adjust the idle mixture screw in small increments, testing after each adjustment, until a smooth idle is achieved without black smoke or hesitation. For mid-range tuning, connect the air-cleaner housing securely and perform a series of throttle pulls to observe how the engine responds to moderate acceleration; adjust the high-speed needle to balance power delivery and fuel economy, avoiding a rich condition that fouls the spark plug or a lean condition that causes overheating. When setting the high-speed jet, perform a final check at full throttle with a loaded cut to verify torque and responsiveness; the engine should accelerate briskly without sudden surges or stalling. Diaphragm wear is a common culprit in carburetor performance; inspect the float, needle valve, and gaskets for signs of cracking or fuel staining, replacing worn parts with OEM components as needed. After adjusting, recheck all fasteners for tightness and ensure the linkage moves freely without binding, as imperfect movement can alter mixture delivery and destabilize performance over time.

Lubrication and cooling system maintenance

Proper lubrication and efficient cooling are critical to the reliable operation and longevity of the Husqvarna 350 chainsaw. Begin by ensuring the engine is cool before performing any servicing to avoid burns and to prevent oil from thinning excessively on a hot engine. Inspect the entire lubrication system for signs of wear, leaks, or blockages, and prepare a clean workspace with approved replacement filters and fresh, manufacturer-recommended lubricants. When servicing, remove any external debris that could contaminate the air intake or oil paths, and keep all fasteners clean and accounted for to prevent reassembly issues. A meticulous approach to lubrication reduces internal friction, minimizes wear on the crankcase, and helps maintain consistent performance under load.

Oil and air filter servicing is essential for maintaining optimal fuel-air mixture and cooling efficiency. Inspect the air filter for dirt, oil saturation, or damage, and replace it if the filter media shows signs of clogging or wear. Clean the filter housing and ensure any pleats are intact to maximize airflow. For the oil filter, verify that the filter element is clean and properly seated within its housing; replace if there are signs of degradation or if the filter becomes difficult to install. After replacing filters, verify the oil pickup and lines are clear of obstructions to prevent oil starvation during operation. Reassemble with appropriate torque on fasteners, and double-check that seals and gaskets are seated correctly to prevent leaks. Regular filter servicing supports engine efficiency, reduces carbon buildup, and extends the service life of the powerhead.

Cooling fins cleaning and heat management are crucial to prevent overheating and to maintain safe engine temperatures during operation. Inspect the cooling fins around the cylinder for dust, sawdust, and debris buildup, which can insulate the fins and impede heat transfer. Use a soft brush or compressed air at low pressure to remove accumulations without bending or damaging the fins. Pay attention to the cooling shrouds and flywheel housing, ensuring there are no obstructions that would reduce airflow. If fins are bent or damaged, carefully straighten them or replace the affected components to restore optimal heat dissipation. Monitor the exhaust port and muffler area for excessive carbon buildup, which can also obstruct heat evacuation; clean using approved methods and tools while avoiding damage to the gasket or mating surfaces. Consistent cooling maintenance helps maintain performance, reduces the risk of detonation, and prolongs engine life under demanding cutting conditions.

In addition to component cleaning, perform a routine inspection of the lubrication reservoir, hoses, and connections for signs of wear, cracks, or leaks. Replace any compromised hose sections and ensure clamps are secure to prevent oil leaks that could create a hazardous working environment. Check the oil pump drive gear and linkage for smooth operation, confirming there is no binding or excessive backlash that could affect oil delivery during operation. After maintenance, run the saw through a brief test at idle and under light load to verify that the lubrication and cooling systems are functioning correctly, listening for unusual noises that could indicate misalignment or a loose component. Documentation of maintenance intervals and observed symptoms helps in planning proactive service, reducing downtime, and maintaining consistent cutting performance.

Electrical system and diagnostics

The electrical system of the Husqvarna 350 is designed to deliver reliable starting, consistent ignition, and stable operation of all engine‑electrical accessories. Begin diagnostics with a thorough visual inspection of the wiring harness, connectors, and grounds for signs of wear, corrosion, or damage. Check for loose connections, melted insulation, or wire chafing that could impede electrical continuity. Use a multimeter to verify that battery terminals are clean and tight, and that ground points are free of rust or paint that could impede grounding. A systematic approach helps isolate faults without unnecessary disassembly and reduces the risk of accidental damage to sensitive components.

When diagnosing electrical faults, establish a baseline by checking for stored fault codes if the system supports it, and note any abnormal indicator lights or abnormal engine behavior. Inspect the ignition coil and stator area for signs of overheating or physical damage, and confirm that the flywheel key has not sheared, which can lead to improper timing. Verify that the kill switch and engine stop circuit are functioning correctly, as a fault in these paths can simulate more serious electrical issues. Document all readings and observations, then compare them to the manufacturer’s specifications to determine whether components require replacement or recalibration.

Battery, spark plug, and fuse checks are essential in restoring reliable operation. Start with the battery, ensuring it is the correct type and voltage for the model, and perform a load test if possible to confirm healthy cranking capability. Inspect battery cables for corrosion, frayed insulation, or loose terminals, cleaning and tightening as needed. Move to the spark plug; remove it and examine the electrode condition, gap, and insulator for fouling, oil deposits, or wear. Replace the spark plug if the electrode gap is out of specification or if there is excessive wear, and always use the recommended heat range and gapping. Finally, inspect all fuses and fuse holders for signs of overheating or loose connections, replacing any blown fuses and reseating holders to ensure solid electrical contact. A clean, well‑maintained electrical system contributes to dependable starting and consistent engine performance in the long term.

Safety and troubleshooting guide

Before performing any maintenance or repair on the HUSQVARNA 350, ensure you have read and understood all safety warnings and operation manuals. Wear appropriate personal protective equipment, including eye protection, gloves, and hearing protection, and work in a well-ventilated area away from bystanders. Disconnect the spark plug boot or battery power source when inspecting, repairing, or replacing saw components to prevent accidental starting. Maintain a clean, organized workspace with a clear area around the machine to avoid tripping hazards and to ensure you can access all controls and components safely. Always use manufacturer-recommended parts and follow torque specifications and fastener patterns to avoid compromising the tool’s integrity and performance.

Common operational issues and fixes: If the chainsaw won’t start, verify the fuel is fresh and mixed according to the manufacturer’s ratio, inspect the spark plug for fouling or wear, and check the air filter for blockages. A stubborn start can indicate a carburetor issue or a clogged fuel line, in which case cleaning or professional service may be required. If the engine loses power during cutting, inspect the bar and chain for proper tension and sharpness, ensure the drive sprocket is not worn, and confirm the air intake is clear of debris. Vibration, unusual noises, or pulsing sensations can signal a loose chain, worn drive sprocket, or misaligned components; stop using the saw and perform a thorough inspection, tightening or replacing parts as needed. For issues with kickback or poor safety bar performance, inspect the chain brake operation, verify the bar nose and bumper is intact, and replace any damaged components to maintain safe cut control. Always consult the service manual for torque specs and service intervals to prevent unintended damage during repairs.

Winching and starting safety considerations: When using a winch or starting a pull-start mechanism, ensure the chain is disengaged and the bar is pointed away from your body to minimize injury risk. Keep the work area clear of bystanders and spectators, and never exceed the recommended load limits of the winching system. Inspect the winch cable or strap for fraying, kinks, or signs of wear before use, and replace if any damage is detected. If the engine requires a warm-up period, perform it on level ground with the chain brake engaged and the bar away from any obstructions. During starting, maintain a firm stance and avoid sudden pulls that could cause kickback or loss of control, and always use full protective gear. Regularly test the chain brake engagement and throttle lock to ensure reliable stopping power and safe operation under load, and document any deviations for professional service assessment.