Stihl MS 311 MS 391 Instruction Manual

Pages 132

Year 2020

Language(s)

of 132

Stihl MS 311 MS 391 Specification

The Stihl MS 311 and MS 391 chainsaws are robust, high-performance models designed for demanding cutting tasks, offering a blend of power, efficiency, and user-friendly features. Both models are powered by a reliable 2-MIX engine, which combines low emissions with fuel efficiency, making them suitable for extended use in various environments. The MS 311 is equipped with a 59.0 cc engine that delivers 4.2 horsepower, while the MS 391 features a slightly larger 64.1 cc engine, generating 4.4 horsepower. Both chainsaws are engineered with an innovative pre-separation air filtration system, which extends the lifespan of the air filter by reducing debris intake, enhancing performance, and minimizing maintenance.

User comfort is prioritized through an advanced anti-vibration system, which significantly reduces fatigue during prolonged use. The ergonomic design includes a side-access chain tensioner, facilitating quick and easy adjustments. Additionally, both models incorporate a high-efficiency oil pump that ensures optimal lubrication, extending the life of the bar and chain. The MS 311 and MS 391 are equipped with a translucent fuel tank, allowing operators to easily monitor fuel levels. Safety features include a QuickStop chain brake for rapid halting of the chain in emergency situations. Weighing 13.67 lbs and 14.11 lbs respectively, these chainsaws balance power with maneuverability, making them ideal for both professional and occasional users. The Stihl MS 311 and MS 391 are engineered to deliver exceptional cutting performance with reliability and ease of operation, meeting the needs of users engaged in demanding forestry and agricultural tasks.

Stihl MS 311 MS 391 F.A.Q.

How do I start the Stihl MS 311/MS 391 chainsaw?

To start the Stihl MS 311/MS 391, ensure the chain brake is engaged. Set the Master Control Lever to the cold start position. Pull the starter rope until the engine fires briefly. Move the lever to the half-throttle position, then pull the starter rope again until the engine runs.

What is the proper way to maintain the chain tension on the MS 311/MS 391?

To maintain proper chain tension, loosen the nuts on the sprocket cover slightly. Use the tensioning screw to adjust the chain so it touches the underside of the guide bar but can still be moved by hand. Tighten the sprocket cover nuts securely after adjusting.

How often should I clean the air filter on my MS 311/MS 391?

The air filter should be checked and cleaned after every 5 hours of operation. If you frequently work in dusty conditions, clean it more often to prevent clogging and maintain optimal performance.

What type of fuel should be used in the Stihl MS 311/MS 391?

The Stihl MS 311/MS 391 requires a 50:1 mixture of gasoline and high-quality 2-stroke engine oil. Use only unleaded gasoline with a minimum octane rating of 89.

How can I troubleshoot a chainsaw that won't start?

Check if the fuel tank is filled with the correct fuel mixture. Ensure the spark plug is clean and functional. Verify that the air filter is clean. If the problem persists, examine the carburetor settings or consult a professional for further diagnosis.

What should I do if the chain on my MS 311/MS 391 is dull?

If the chain is dull, sharpen it using a round file and file guide that matches the chain's specifications. Maintain the correct angles and depth gauges. Alternatively, replace the chain if it's too worn or damaged.

How do I properly store the Stihl MS 311/MS 391 chainsaw?

For long-term storage, empty the fuel tank in a well-ventilated area and run the engine until it stops. Clean the chainsaw thoroughly, including the guide bar and chain. Store it in a dry place, away from direct sunlight and moisture.

Why does my MS 311/MS 391 chainsaw keep stalling during operation?

Stalling can be caused by a clogged air filter, a dirty carburetor, or incorrect fuel mixture. Clean the air filter, inspect the carburetor, and ensure the fuel is fresh and properly mixed. Adjust the carburetor settings if necessary.

How do I replace the spark plug on the MS 311/MS 391?

To replace the spark plug, remove the top cover of the chainsaw to access the spark plug. Use a spark plug wrench to unscrew and remove the old plug. Install a new spark plug of the same type, ensuring it is tightened securely.

What safety precautions should I take while operating the Stihl MS 311/MS 391?

Always wear personal protective equipment such as gloves, safety glasses, ear protection, and chainsaw chaps. Ensure the chain brake is engaged when starting the chainsaw. Maintain a firm grip and stable footing while operating to prevent accidents.