STIHL MS 311 Service Manual

Overview

The STIHL MS 311 is a versatile mid-range chainsaw designed for demanding cutting tasks in both professional and serious hobbyist settings. It combines a robust 2-stroke engine with a balanced chassis and ergonomic handling to minimize operator fatigue during extended periods of use. Understanding the core construction and operating principles helps technicians diagnose issues more quickly, perform routine maintenance with confidence, and ensure the saw operates safely and at peak efficiency. This section provides foundational context for safe operation, routine servicing, and correct setup before engaging in any cutting tasks.

Before performing any service work, it is essential to review safety protocols and ensure the work environment is prepared to support maintenance activities. Proper PPE, such as cut-resistant gloves, eye protection, hearing protection, and steel-toed boots, helps mitigate common hazards associated with chainsaw maintenance and operation. A clean, well-lit workspace with adequate ventilation reduces the risk of inhaling fumes and allows for precise inspection of components. Establish a clear workflow that includes power-down procedures, depressurization of the fuel system if required, and verification of fuel and oil levels prior to testing the saw after service.

The MS 311 employs a scavenging-driven carbureted two-stroke engine paired with a chainsaw bar and chain. Maintenance and inspections typically focus on the fuel system, ignition timing, carburetor adjustments, clutch function, bar and chain lubrication, and air filtration. Proper tool selection and workspace organization streamline the service process and minimize the chance of damage to components or personal injury. By following a structured approach to diagnostics and maintenance, technicians can extend the life of the saw, improve performance, and maintain consistent cutting efficiency across varied workloads.

In this overview, emphasis is placed on safety, personal protective equipment, and the initial setup required to begin any service task. Understanding PPE requirements and establishing a dedicated, orderly workspace are foundational steps that support all subsequent maintenance activities. The following considerations outline how to prepare safely, identify common risk factors, and set the stage for thorough, methodical servicing of the STIHL MS 311. Proper preparation reduces downtime, enhances accuracy in repairs, and contributes to a longer service life for the equipment.

Safety and personal protective equipment

Personal protective equipment (PPE) is the first line of defense when working on or around chainsaws, and it should always be chosen based on the specific maintenance task and potential hazards. For maintenance work, select cut-resistant gloves, eye protection with side shields, and hearing protection rated for high-decibel work environments. A sturdy, snug-fitting apron or chaps designed for chainsaw use can protect the legs from incidental contact with the chain, while steel-toed boots provide reliable foot protection. In addition to PPE, maintain a clean work area free of tripping hazards, and keep a first aid kit and fire extinguisher readily accessible in case of emergencies.

Prior to any service, disconnect the spark plug wire and ensure the engine cannot start. This simple safety step prevents accidental ignition while you are inspecting or disassembling components. When working with the fuel system, work in a well-ventilated area and avoid open flames or sparks. Use appropriate containers to drain any fuel or oil, and follow local hazardous waste disposal guidelines for used oil or fuel-soaked materials. Consistently verifying that the saw is secure on a stable work surface reduces the likelihood of slips or drops during maintenance tasks.

When evaluating electrical components or sensors, inspect for signs of wear, corrosion, or loose connections. Any damaged wiring or insulation should be addressed before proceeding, as it can create safety risks or intermittent operation issues. PPE selection should be revisited if you encounter unusually solvent-rich vapors or hot surfaces that could cause skin burns or respiratory irritation. Always follow the manufacturer’s safety recommendations and consult the service manual if you are uncertain about a procedure or torque specification.

Tools and workspace setup

A well-equipped maintenance space includes a baseline set of hand tools, torque wrenches, and specialty gauges appropriate for precisely servicing the MS 311. Common tools include metric Allen keys, a set of small screwdrivers, feeler gauges, pliers, a flywheel puller if needed, and a suitable carburetor synchronization tool. A magnetic tray helps keep fasteners organized, while a parts tray or small bins assist in tracking screws and washers during disassembly. Establish a clean, static-free surface with adequate lighting to simplify inspection and reassembly tasks.

Storage and organization are critical in preventing cross-contamination and lost hardware. Use labeled containers for different subassemblies such as the carburetor, fuel system, ignition, and bar/chain components. Keep the instruction manual or service sheets accessible for torque specs, lubrication recommendations, and sequence notes. A simple bench vise or clamp system can stabilize the saw during intricate tasks, and a low-profile extractor tool may be needed for stubborn fasteners without marring the surfaces. Regularly calibrate or verify the accuracy of measuring tools to ensure precise diagnostics and consistent maintenance results.

Product overview and specifications

The STIHL MS 311 is a mid-range chainsaw designed for skilled homeowners and semi-professional users who require reliable cutting performance in a variety of conditions. It balances power, weight, and durability to handle routine felling, limb removal, and firewood processing. The design emphasizes ease of serviceability, with accessible air filtration and carburetor adjustments that allow technicians to optimize performance in the field. Ergonomic features such as a well-positioned handle, balanced weight distribution, and vibration-damping components contribute to reduced user fatigue during extended cutting sessions. Overall, the MS 311 is built to deliver consistent cutting efficiency while maintaining reliability under demanding outdoor use.

Chain saw model details encompass the essential identifiers that distinguish the MS 311 from other STIHL models. The unit typically features a robust chassis with a magnesium or aluminum components construction to minimize weight while preserving rigidity. In service, technicians should verify the model serial number, bar length compatibility, and chain pitch to ensure correct replacement parts and proper operation. The tool is designed to operate with a range of guide bars and chains, allowing users to tailor performance to the task at hand, such as longer bars for rapid felling or shorter bars for precision work in tight spaces. Regular inspection of the bar mounting hardware, anti-kickback components, and chaining mechanism is critical for safe and efficient operation.

Technical specifications and ratings cover the performance envelope of the MS 311. Typical power output is rated in the mid-range for consumer/professional mid-tier chainsaws, with a displacement that supports steady cutting without excessive fuel consumption. The mowing of these specifications, including maximum RPM, idle speed, fuel requirements, and lubrication flow, is essential during setup and routine maintenance to prevent overheating and wear. Fuel system specifications emphasize the importance of using the correct fuel-oil mixture, fuel type, and quality, as well as ensuring good air-fuel ratios under varying load conditions. In service, technicians should monitor compression values, carburetor settings, and spark timing to maintain optimal performance and compliance with safety and emissions standards.

Key components and functions are described to assist in diagnosing wear, damage, and malfunctions. The engine assembly comprises the crankcase, cylinder, piston, and connecting rod, all of which require periodic inspection for scoring, overheating, and lubrication adequacy. The carburetor governs the air-fuel mixture and is paired with a muffler, spark plug, and ignition module that synchronize to deliver reliable starts. The chain brake, clutch, and sprocket assembly control engagement and smooth transmission of power to the chain, while the anti-vibration system reduces operator fatigue and component stress. Understanding the interaction of the bar, chain, drive mechanism, and chain catcher is essential for safe operation and timely preventive maintenance, including proper tensioning, lubrication, and chain sharpness checks.

In addition to these core elements, routine maintenance procedures for the MS 311 emphasize air filtration, fuel system upkeep, and cooling passages to prevent dirt ingestion and overheating. Proper cleaning of the air intake, inspection of the air filter media, and replacement when necessary are fundamental steps for maintaining engine longevity and performance. The cooling system, including flywheel fins and cooling passages, should be inspected for debris buildup, which can impair heat dissipation. Regularly checking and replacing worn gaskets, seals, and o-rings helps preserve compression and fuel efficiency. Finally, a systematic approach to lubrication—ensuring proper bar and chain oiling—prolongs chain life and reduces friction-induced wear during operation.

Initial inspection and preparation

The STIHL MS 311 is a high-performance chainsaw designed for demanding cutting tasks, and a thorough initial inspection ensures reliable operation from the moment you first start the tool. Begin by inspecting the exterior housing for any signs of damage, cracks, or missing fasteners. Check that the bar and chain are properly mounted and tensioned according to the manufacturer’s specifications, and verify that the chain brake engages smoothly. Confirm that all control levers, including the throttle lockout, on/off switch, and chain catcher, move freely without binding. Make sure the spark plug boot is intact and that the fuel cap seals securely to prevent leaks during operation. A clean, undamaged air filter housing should be present, with the air filter itself free of obstructions to promote efficient combustion and reduced exhaust emissions.

During initial checks, verify that the tool’s decals and warning labels are legible and in place, and inspect the engine cooling system for any blockages or debris that could impede airflow. Ensure that the chain tensioning mechanism operates smoothly and that the bar oiling system delivers oil to the chain as expected when the engine is running. If you notice any abnormal sounds, vibrations, or hesitation during idle, isolate the unit and perform a more detailed inspection of the clutch, pulley, and drive components. Document any irregularities and address them before loading the saw for work to prevent potential safety hazards or premature wear.

Safety device verification involves testing all protective features to confirm they function correctly under load conditions. Engage the chain brake and attempt to move the chain by hand with the clutch disengaged; the chain should remain stationary. Re-engage the throttle lockout and verify that the throttle return spring returns to the idle position promptly when the trigger is released. Check the anti-vibration system for signs of wear and ensure that vibration mounts are intact and properly seated. Confirm that the chain catcher is present and secure, as this component reduces the risk of kickback injuries. Finally, confirm that the muffler and spark arrestor are free of obstructions and that there are no exhaust leaks around the gasket or seals. A thorough test of all safety devices before fueling or starting the saw is essential to operator protection and equipment longevity.

Fuel and oil system preparation is critical for optimal performance and longevity of the MS 311. Use the recommended STIHL two-stroke fuel mixture and the correct oil type specified in the manual, mixed to the correct ratio. Inspect the fuel and bar oil tanks for cracks or seepage, and ensure the caps seal properly to prevent contamination or evaporation. Prime the fuel system according to the procedure for a cold start, and verify that the fuel lines are free of cracks or kinks, replacing any damaged hoses as needed. With the engine off, confirm that the carburetor adjustments meet specification, and check for any fuel leaks around the carburetor petcock or connections. Finally, prepare the bar oil system by filling the bar oil reservoir and ensuring that the oiling nozzle and nozzle line are free of obstructions; a properly functioning bar oil system is essential for maintaining bar and chain life and consistent cutting performance.

Starting and operating procedures

Cold start procedure begins with ensuring the equipment is on a stable, well-ventilated surface in a clean workspace. Check the chain brake, chain tension, and bar oil reservoir before engaging any start procedures. Move the choke lever to the full choke position if the engine is very cold, and ensure the eliminating of fuel leaks or loose fittings around the carburetor area. Prime the fuel system if your model requires priming, using the primer bulb until you feel resistance, which indicates that the carburetor is filled with fuel. With the master switch in the on position, place the saw on the ground with the bar away from your body, holding the front handle firmly while gently pulling the starter rope until you feel a light resistance, then pull briskly to start. Allow the engine to run at idle for a short period to warm up, and gradually move the choke to the half- or full-open position as the engine comes to life and shows steady operation. Never attempt to start the saw in a locked state or with loose clothing near rotating parts, and always maintain a secure stance to avoid kickback during the starting process.

Warm start procedure is used when the engine is still warm from previous operation or after a brief shutdown. Begin by confirming that the throttle and chain brake are in the correct neutral positions, and that the bar is away from any obstructions. If the engine was recently running, you may need only a partial choke or none at all; adjust the choke according to the engine’s sound and RPMs. Position the saw securely, with the path of the bar clear, and apply a smooth, controlled pull on the starter rope to bring the engine to life. Allow a moment for the fuel mixture to stabilize in the carburetor, then gently release the choke and bring the engine to a steady idle before applying throttle. Throughout the warm-start process, ensure adequate ventilation and avoid sudden acceleration that could unsettle the saw or cause kickback. Regularly inspect the air filter, spark plug, and fuel lines to maintain reliable starting performance during repeated warm starts.

Operating guidelines and tips emphasize safe and efficient use of the STIHL MS 311 during regular work. Maintain a firm stance with both hands on the saw, keeping your elbows slightly bent to absorb vibration and reduce fatigue. Before engaging the throttle, verify that the chain brake is disengaged and that the chain is properly tensioned to prevent dangerous slippage; avoid chain contact with the ground or other hard surfaces that could dull teeth or cause kickback. When cutting, use a smooth, progressive throttle motion and avoid forcing the saw through material; let the engine's torque and chain speed do the work. Regularly check chain tension and lubrication, ensuring the bar oil reservoir is filled and that the oil flow is consistent during operation. In dusty or dirty environments, increase maintenance checks for air filter cleanliness, muffler isolation, and fuel quality to maintain optimal running conditions and prolong the service life of the saw. Always wear appropriate safety gear, including eye protection, hearing protection, gloves, and sturdy footwear, and keep bystanders at a safe distance to uphold a safe working environment.

Performing daily maintenance on your STIHL MS 311 helps ensure reliable starts, reduced wear, and longer component life. Begin each use with a quick visual inspection of the machine, checking for loose fasteners, damaged guards, and any fuel leaks. Wipe down the exterior to remove dust, debris, and oily residues, paying special attention to the air intake near the starter housing. Verify that the bar and chain are properly tensioned according to the manufacturer’s spec and that the chain brake functions smoothly. Each day, ensure the chain is sharp and free of nicks or cracks, and lubricate the bar rails with a light coating of bar oil to minimize friction during operation. Finally, confirm that the fuel level is appropriate and that there are no signs of stale fuel or varnish in the tank or lines, which can impair performance from the first pull of the engine.

Scheduled service intervals are the primary way to prevent major failures and maintain peak performance. Follow the interval recommendations in the service manual based on operating hours and environmental conditions. Use genuine STIHL replacement parts for all service activities to preserve safety and efficiency. At each interval, inspect the cooling fins, muffler, and exhaust ports for signs of carbon buildup or obstruction, and clean as needed to maintain proper exhaust flow. Check the fuel filter, air filter, and carburetor linkage for wear and proper operation, replacing any components that show signs of degradation. Record all maintenance actions with date and hours to build a traceable history for future service planning and resale value.

Bar and chain care is a critical area where proper technique directly influences cutting performance and safety. Inspect the bar for abnormal wear or bends, and ensure the sprocket nose is intact. Square the bar by checking that the bar tip remains in alignment with the chain drive, and file or replace as necessary to maintain a uniform edge. The chain should be tensioned according to the chain manufacturer’s guidelines, ensuring it cannot drag on the guide bar but still moves freely by hand. Lubricate the chain with fresh bar oil suitable for your climate, and verify that the oiling system delivers a steady flow during operation. When sharpening, maintain the factory tooth geometry and avoid over-sharpening, which can lead to premature wear and increased kickback risk.

Air filter and fuel system maintenance are essential for consistent performance and fuel efficiency. Inspect the air filter element for dirt, oil, or damage after every long or dirty cut, and replace it if it is clogged or degraded. Use fresh, clean fuel and an appropriate stabilizer if the saw will sit unused for an extended period. Check the fuel lines for cracks, stiffness, or leaks, replacing any suspect lines to prevent air and fuel starvation. Clean or replace the carburetor intake screen if the saw exhibits rough idling or poor acceleration, and verify that the carburetor is properly synchronized. Keep the air intake and cooling system free of debris to avoid overheating, which can shorten engine life and reduce performance.

Spark plug and ignition system care ensure reliable starting and smooth operation across varying temperatures. Remove the spark plug and inspect the electrode gap, replacing the plug if the insulation is cracked, the electrode is worn, or fouling is present. gapped correctly; adjust to the manufacturer’s specified interval. Clean any carbon buildup from the spark plug threads and seal with a light coating of anti-seize compound if recommended. Check the ignition coil and spark plug wire for signs of damage or wear, and replace any compromised components to prevent misfires. After maintenance, reinstall the plug finger-tight, then torque to the specified value, and perform a brief test cut in a safe area to confirm steady operation before resuming normal work.

The STIHL MS 311 is a robust chainsaw designed for demanding outdoor work, and understanding common operating issues helps you maintain reliable performance. When the saw fails to start or runs poorly, always begin with a visual inspection of the basics: check the fuel supply forExpiry and contamination, verify the air filter is clean, and confirm that the spark plug is in good condition with correct gap. Poor starting performance can also be caused by a clogged carburator passage or an improperly adjusted idle speed, so it’s essential to proceed with a methodical assessment of the fuel system, air intake, and ignition system. In addition, inspect the chain brake for engagement, ensure the chain oiling system is functioning, and look for unusual noises or vibrations that could indicate a loose bar nut or damaged bar. Regular maintenance routines, including air filter cleaning, spark plug replacement, and fuel stabilization, significantly reduce the incidence of common issues and extend the service life of the saw.

The troubleshooting guide below offers symptom-based steps to quickly identify and address problems with the STIHL MS 311. Begin with the most common causes and progressively work toward more detailed checks. If the saw fails to start, verify fuel quality, confirm the compression is within specification, and inspect the ignition system for a strong spark. If the engine starts but stalls or runs erratically, inspect for air leaks in the intake boot, carburetor settings, and possible fuel starvation due to a clogged fuel filter or contaminated fuel. For smoking, overheating, or loss of power, examine the cooling system, exhaust path, muffler screen, and the presence of any debris in the combustion chamber. When you observe abnormal vibrations or indications of mechanical wear, inspect the bars, chain, clutch, and sprocket for wear patterns and proper tension, as these components directly influence performance and safety.

Common operating issues frequently include difficult starting, lack of power, black smoke, chain not moving smoothly, or the saw shutting off suddenly. Each symptom aligns with a set of checks that can be performed safely without disassembling critical components. Start with the simplest steps—fuel and air filters, spark plug condition, and chain brake status—and progressively move to more involved tests such as carburetor adjustment and compression checks. Always follow safe work practices, disconnect the spark plug boot before handling ignition components, and wear appropriate PPE. By maintaining a routine of preventative maintenance and promptly addressing symptoms, you can minimize downtime and keep the STIHL MS 311 performing at peak efficiency.

When diagnosing or deciding whether to service or replace parts, consider the age of the saw, hours of operation, and the current condition of key components. If compression is low, or if the muffler shows significant carbon buildup that cannot be safely cleaned, resurfacing or replacing parts may be necessary to restore power. A worn chain and bar can cause inefficiencies and kickback risks, so replace when wear indicators show excessive thinning. Carburetor issues that resist adjustment may require professional cleaning or replacement, especially if fuel contamination or varnish buildup is evident. For safety-critical parts like the ignition module or seals, weigh the cost of replacement against the risk of failure during operation; in many cases, proactive replacement provides better long-term reliability and safety. Regularly scheduled service intervals and using genuine STIHL parts help ensure continued performance and safety of the MS 311 in rugged outdoor conditions.

Disassembly and reassembly procedures

Disassembly begins with ensuring the saw is completely powered down and the spark plug boot is removed to prevent any accidental ignition or electrical shorts. Begin by draining any remaining fuel from the tank and blanket-covering the area with a clean work surface to prevent contamination. Use the proper T-handle or socket wrenches to detach the fuel lines and ignition components carefully, labeling each connection to ensure accurate reassembly. As components are removed, photograph or document their orientation to aid in accurate placement later, and set parts on a labeled tray to avoid misplacement. When removing the clutch cover, verify the chain brake is engaged and that the chain is secured to prevent injury or damage during the process.

Component by component inspection involves examining each part for wear, cracks, or deformation, starting with the bar nuts, fuel lines, and air intake system. Inspect the filter and air passages for obstructions that could restrict airflow and affect engine performance; replace filters if they show signs of excessive dust or damage. The cooling fins should be checked for carbon buildup or debris that could impede cooling; clear any obstruction with a soft brush or plastic scraper without damaging the fins. Move to the ignition module, spark plug, and wiring, ensuring the plug electrode gap matches the manufacturer specification and that there is no corrosion or loose connections. Inspect the bar and chain for proper tension, wear on the drive links, and any abnormal back-and-forth movement, replacing components as necessary to maintain safe operation.

Reassembly considerations and torque references require precise alignment of all components and correct fastener torque to ensure reliability and safety. Start by reinstalling the bar and chain, ensuring the chain is properly oriented with the drive links engaging the sprocket and guide ramp, followed by the correct chain tension as specified by STIHL for the MS 311 model. Tighten clutch cover screws to the recommended torque in a crisscross pattern to ensure even seating, and verify the chain brake mechanism engages and disengages smoothly. Reconnect the fuel lines and vacuum hoses with new clamps if needed, and reinstall the fuel tank with attention to gasket integrity to prevent leaks. Reattach the spark plug and ignition leads in the correct order, then perform a careful pre-start check to confirm that there are no loose parts or potential binding conditions that could cause engine damage or unsafe operation. Finally, verify that all safety systems, including the chain brake and throttle lockout, are functioning correctly before returning the saw to service.

The STIHL MS 311 is a precision-engineered chainsaw that relies on durable, properly matched parts to maintain performance and safety. Correct part identification is essential before any repair or replacement begins to avoid installing mismatched components that could compromise operation. Start by consulting the model’s serial number and approved parts list to confirm compatibility, and use OEM or OEM-equivalent components from reputable suppliers. When sourcing, verify part numbers against the manufacturer's schematic and maintain clear records of what was installed for future service intervals. Take care to inspect packaging for damage and ensure that any missing seals or fasteners are replaced with exact equivalents to preserve the device’s analytical tolerances and safety features. Proper documentation and sourcing discipline reduce return visits and extend the tool’s service life significantly.

Common wear parts on the STIHL MS 311 include items such as air filters, fuel filters, spark plugs, oil filters, chains, bars, and gaskets. Regular inspection of these components is critical, especially for chains and bars where wear directly affects cutting performance and safety. Replace air and fuel filters at manufacturer-recommended intervals or sooner in dusty or high-load environments to sustain optimal air-fuel mixture and engine cooling. Spark plugs should be checked for correct gap, fouling, and discoloration, with replacements chosen to match the specified heat range. Gaskets and seals should be inspected for hardening, cracking, or leakage, and replaced to prevent air or oil leaks that can alter engine pressure and performance. When replacing wear parts, always follow torque specifications and use new fasteners where required to maintain vibration resistance and proper clamping force. Finally, keep a routine maintenance log to track part lifespans and anticipate upcoming replacements before performance deteriorates.

Reassembly validation and testing involve methodical checks to ensure each component is correctly installed and functions as intended. Begin by confirming that all fasteners are torqued to the manufacturer’s specifications using a calibrated torque wrench, paying attention to sequence patterns for gaskets and covers to avoid distortion. After reassembly, perform a leak test on fuel and oil lines to detect any pressure losses that could indicate a degraded seal or improper routing. Conduct a choke and starting procedure to verify that the engine transitions from idle to full operation smoothly, listening for unusual noises such as knocking or pinging that could signal improper timing or component misfit. Perform a live-run test under load conditions to assess chain brake engagement, chain lubrication delivery, and bar seating, ensuring no abnormal vibrations or heat buildup. If any fault codes or diagnostic indicators are present on your service tools, record them and address the root cause before returning the saw to service. Documentation of test results, adjustments, and component replacements is essential for traceability and future maintenance planning.

Safety and compliance information

The STIHL MS 311 requires careful attention to safety protocols to prevent injury and device damage during operation, maintenance, and transport. Before conducting any work, ensure you have the appropriate PPE, including eye protection, cut-resistant gloves, hearing protection, and sturdy footwear. Inspect the saw for any signs of damage or wear, such as loose fasteners, cracked housing, or frayed wires, and address issues before use. Always disengage the spark plug cap or remove the battery (if applicable) and disconnect the chain brake when performing maintenance to avoid accidental starts. Establish a clean, well-lit workspace free of debris, and keep bystanders at a safe distance to minimize risk during startup and operation.

Hazard analysis and risk mitigation involve identifying potential failure modes and applying controls to reduce the probability and consequence of those failures. Begin with a pre-operation check that includes bar and chain tension, chain sharpness, fuel level, and oil lubrication, ensuring the chain cannot move when the saw is idle. Use the correct fuels and oils specified by STIHL, and adhere to the recommended storage of flammable liquids away from ignition sources. Maintain a firm grip, stable stance, and use two-handed operation to maximize control, especially when cutting overhead or on uneven terrain. If kickback risk is present, adopt the stance and technique outlined in the manual, and replace worn bars or chains promptly to sustain safe cutting conditions. Regularly review safety data sheets for all chemicals used in maintenance and dispose of waste and used filters in accordance with local regulations.

Regulatory and warranty considerations require documentation of compliance with local and national laws governing the use and maintenance of outdoor power equipment. Verify that the saw is registered with the manufacturer if required, and keep proof of purchase, maintenance records, and service dates accessible in the event of a warranty claim. Do not modify the saw with aftermarket parts that could compromise safety or void the warranty; use only STIHL-approved components and replacement chains. Follow applicable environmental regulations when disposing of old fuel, oil, and filters, and ensure emissions controls or spark arrestor guidelines are respected where mandated by local authorities. For professional service, rely on trained technicians who follow certified procedures to preserve warranty validity and maintain high safety standards during inspections and repairs.

Safe storage and transportation practices protect the equipment and operators from damage and injury when not in use or during movement. Store the MS 311 in a dry, well-ventilated location away from heat sources, children, and pets, with the chain disengaged and the bar cover in place. Use the original container or a dedicated storage case to protect delicate components and prevent fuel leaks; ensure the fuel is fresh and properly sealed before storage. During transportation, secure the saw in a stable position to prevent shifting, and avoid transporting with the chain tensioned or the bar extended. When transporting in a vehicle, keep the unit upright and disconnected from any power sources, and follow local transport regulations for flammable liquids if fuel must accompany the equipment. Regularly inspect storage conditions for signs of moisture or corrosion and perform routine maintenance before returning the saw to service to maintain compliance and readiness for safe operation.

Appendix and resources

The STIHL MS 311 service manual appendix consolidates critical information that technicians rely on during routine maintenance and complex repairs. This section provides detailed guidance on lubricants and fuels specifications, ensuring that fuel stability, octane rating, and lubrication requirements align with STIHL’s engineering standards. Proper selection and handling of lubricants help extend engine life, reduce wear, and maintain optimal compression and performance. By adhering to these specifications, technicians can minimize downtime and improve reliability across a range of operating conditions.

Lubricants and fuels specifications for the MS 311 cover chainsaw oil, bar and chain oil, spark plug gaps, and the correct fuel mixture. It is essential to verify viscosity ratings, approved additive packages, and compatibility with ethanol-containing fuels. The manual emphasizes using fresh, clean fuel and avoiding contamination from moisture or particulates, which can lead to degraded performance or corrosion within the fuel system. Maintaining proper lubrication at the bar and chain reduces friction and heat buildup, contributing to smoother operation and longer service intervals. Adhering to these guidelines also supports seamless cold-weather starts and consistent throttle response during demanding cutting tasks.

Recommended tools and torque chart provide technicians with precise specifications for fasteners, bolts, and components unique to the MS 311. The chart helps ensure correct assembly torque to prevent over-tightening or under-tightening, which can cause threaded failures or misalignment. Using calibrated torque wrenches and following the manufacturer’s sequence for fastener tightening promotes uniform clamping force and reliable performance. The tools list includes specialty items such as feeler gauges, feeler blocks, and pullers designed for chain brake, clutch, and sprocket assembly. Keeping this tool set organized and within reach reduces downtime and enhances workflow efficiency during service sessions.

Manufacturer contact information is provided to assist service technicians with obtaining genuine parts, updated service bulletins, and technical support. The contact details include regional distributors, parts availability, and warranty service processes. It’s crucial to reference the correct contact channel for your geographic area to ensure prompt and accurate guidance. The documentation also outlines typical response times and the information needed when contacting support, such as model serial numbers, engine type, and observed fault symptoms. Maintaining direct lines of communication with STIHL’s service network helps technicians resolve complex issues quickly and maintain the instrument’s performance and safety standards for end users.

Throughout the appendix, the emphasis remains on accuracy, safety, and adherence to STIHL’s certified procedures. Technicians should cross-check any updates or revisions to the manual with the official STIHL website or authorized distributors. Regularly reviewing the lubricants and fuels specifications, torque recommendations, and manufacturer contact pathways ensures that service work remains compliant and traceable. By following these resources meticulously, technicians can deliver consistent, high-quality maintenance that preserves performance, reliability, and safety for the MS 311 across its service lifespan.