manual stihl ms 251

Stihl MS 251⁚ A Comprehensive Guide

The Stihl MS 251 is a popular and versatile chainsaw that is perfect for a wide range of tasks, from cutting firewood to clearing brush. This comprehensive guide will provide you with all the information you need to know about the Stihl MS 251, from its key features to its maintenance and care. We will also cover safety precautions, working techniques, troubleshooting common issues, and recommended accessories. Whether you are a seasoned professional or a novice chainsaw user, this guide will help you get the most out of your Stihl MS 251.

Introduction

The Stihl MS 251 is a powerful and reliable chainsaw designed for a variety of tasks, from cutting firewood to clearing brush and even light construction work. This chainsaw is known for its robust build, smooth operation, and user-friendly features. It is a popular choice among both professionals and homeowners due to its balance of power and maneuverability. The Stihl MS 251 is powered by a single-cylinder, two-stroke engine, and features an electronic ignition system for easy starting. It is equipped with a fuel system that includes an all-position diaphragm carburetor, ensuring consistent performance in any position. The MS 251 is available in two versions⁚ the standard MS 251 and the MS 251 C, which comes with a 40 cm bar.

This manual serves as a comprehensive guide to the Stihl MS 251, providing essential information on its features, operation, maintenance, and safety. Whether you are a seasoned chainsaw user or a beginner, this manual will equip you with the knowledge and skills to operate the MS 251 safely and efficiently. From understanding the engine specifications to mastering cutting techniques and troubleshooting common issues, this manual covers all aspects of the MS 251, ensuring you can maximize its potential and enjoy years of reliable service.

Key Features of the Stihl MS 251

The Stihl MS 251 boasts a range of features designed to enhance its performance, user experience, and safety. Some of its key features include⁚

• Powerful Engine⁚ The Stihl MS 251 is equipped with a robust, single-cylinder, two-stroke engine, delivering ample power for various cutting tasks. Its efficient design ensures consistent performance and reliable operation.
• Electronic Ignition⁚ The electronic ignition system ensures easy starting, even in cold weather conditions. This feature eliminates the need for manual adjustments, making the MS 251 more convenient to use.
• All-Position Diaphragm Carburetor⁚ The MS 251 features an all-position diaphragm carburetor, allowing for consistent fuel delivery even when the chainsaw is tilted or operated in different positions. This ensures reliable performance in various working conditions.
• Anti-Vibration System⁚ The Stihl MS 251 incorporates an advanced anti-vibration system to minimize hand and arm fatigue during extended use. This feature provides enhanced comfort and reduces the risk of operator discomfort.
• Easy-Access Air Filter⁚ The MS 251 features an easy-access air filter system, simplifying maintenance and allowing for quick filter replacement. This feature ensures optimal engine performance and prolongs the life of the chainsaw.

These key features make the Stihl MS 251 a versatile and user-friendly chainsaw for a wide range of applications, from cutting firewood to clearing brush and light construction work.

Engine Specifications

The Stihl MS 251 is powered by a robust, single-cylinder, two-stroke engine that delivers ample power for a range of cutting tasks. Here are the key engine specifications of the Stihl MS 251⁚

• Displacement⁚ 50.2 cc
• Power Output⁚ 3.4 hp (2.5 kW)
• Fuel Mixture Ratio⁚ 50⁚1 (Gasoline to Oil)
• Fuel Tank Capacity⁚ 0.55 liters (1.5 pints)
• Oil Tank Capacity⁚ 0.25 liters (0.7 pints)
• Ignition System⁚ Electronic magneto ignition
• Air Filtration⁚ Dual-stage air filter

The Stihl MS 251’s engine specifications highlight its balance of power and efficiency. Its robust design and efficient fuel consumption allow for extended operation while maintaining a high level of performance.

Cutting Attachment

The Stihl MS 251 is designed to be versatile and accommodate various cutting tasks. Its cutting attachment, the bar and chain, plays a crucial role in achieving precise and efficient cuts. Here’s a breakdown of the key aspects of the Stihl MS 251’s cutting attachment⁚

• Guide Bar⁚ The Stihl MS 251 can accept guide bars ranging from 16 to 18 inches in length. The specific bar length you choose will depend on the size of the trees or branches you’re cutting. It is important to note that the actual cutting length may vary slightly based on the powerhead used.
• Chain⁚ The Stihl MS 251 uses a 3/8″ pitch, 1.3 mm gauge chain. The chain is responsible for cutting through the wood, and the sharpness of the chain is crucial for achieving smooth and efficient cuts. Regular chain sharpening is essential for optimal performance and safety.
• Chain Tensioning System⁚ The Stihl MS 251 features a reliable chain tensioning system that allows for quick and easy adjustments. Proper chain tension is essential for safe and efficient operation, as a loose chain can slip and cause kickback.

The choice of bar and chain length, as well as the chain’s sharpness, is vital for successful cutting. Understanding the proper selection and maintenance of these components will enhance the Stihl MS 251’s performance and ensure safe operation.

Safety Precautions

Operating a chainsaw like the Stihl MS 251 requires a high level of awareness and adherence to safety protocols. The following safety precautions are essential for minimizing the risk of accidents and ensuring a safe working environment⁚

• Protective Gear⁚ Always wear appropriate safety gear, including a helmet, eye protection, hearing protection, gloves, and sturdy work boots. These items provide vital protection against potential injuries from flying debris, loud noise, and accidental contact with the chain.
• Chain Saw Maintenance⁚ Regularly inspect and maintain the chain saw, ensuring the chain is sharp, properly tensioned, and lubricated. A well-maintained chainsaw is less likely to malfunction or experience kickback, which can cause serious injury.
• Proper Handling⁚ Never operate the chainsaw with one hand. Always use a firm two-handed grip and keep your fingers away from the chain. Be aware of your surroundings and ensure that there are no obstacles or people in the area before starting the saw.
• Kickback Awareness⁚ Kickback is a sudden, forceful backward movement of the saw that can occur if the chain encounters an obstacle or if the saw is not properly controlled. Always be aware of the potential for kickback and use proper cutting techniques to minimize the risk.

By following these safety precautions, you can significantly reduce the risk of accidents and ensure a safe and productive experience when using the Stihl MS 251.

Working Techniques

Mastering the art of using a chainsaw like the Stihl MS 251 involves understanding proper cutting techniques that ensure efficiency, safety, and a clean cut. Here are some essential working techniques to keep in mind⁚

• Starting the Cut⁚ Begin each cut by placing the saw firmly on the log with the tip of the bar slightly elevated. Apply gentle pressure to the saw as you start the cut. Avoid forcing the saw into the wood, as this can lead to kickback.
• Cutting Angle⁚ Maintain a slight angle (around 10-15 degrees) when cutting to prevent the saw from binding or getting stuck. This angle ensures smoother cutting and reduces the risk of kickback.
• Limb Removal⁚ When removing limbs, make two cuts. The first cut should be a notch on the underside of the limb, followed by a second cut on the topside, slightly above the notch. This technique prevents the limb from falling and potentially damaging the saw or causing injury.
• Bucking⁚ Bucking (cutting logs into shorter lengths) should be done with a combination of cuts. Begin with a notch cut on the topside of the log, followed by a cut on the underside to create a “V” shape. This ensures a controlled fall of the log and reduces the risk of the saw binding.

Practice these techniques regularly to develop a smooth and efficient cutting style that minimizes the risk of accidents and maximizes your productivity with the Stihl MS 251.

Maintenance and Care

Regular maintenance is crucial for extending the lifespan of your Stihl MS 251 and ensuring its optimal performance. Here’s a guide to proper maintenance and care⁚

• Air Filter⁚ Clean the air filter after every 10 hours of operation or more frequently if working in dusty conditions. A dirty air filter restricts airflow to the engine, leading to reduced power and increased wear. Use compressed air to blow out any debris from the filter.
• Spark Plug⁚ Check and clean the spark plug every 25 hours of operation or more frequently in demanding conditions. A fouled spark plug can cause difficult starting and poor performance. Use a wire brush to clean the electrode and gap the plug to the manufacturer’s specifications.
• Chain⁚ Sharpen the saw chain regularly to maintain optimal cutting performance and reduce strain on the engine. A dull chain requires more force to cut, leading to increased wear and tear. Use a chain saw file to sharpen the teeth, maintaining the correct angle and depth.
• Bar⁚ Inspect the bar for any signs of wear or damage. Replace the bar if it is worn or damaged, as this can lead to safety issues and reduced cutting performance.
• Fuel System⁚ Drain the fuel tank and carburetor before storing the chainsaw for extended periods. This prevents gumming and clogging of the fuel system. Always use fresh fuel and avoid storing the saw for long periods with old fuel.

Following these maintenance tips will ensure your Stihl MS 251 runs smoothly and efficiently for years to come.

Troubleshooting Common Issues

While the Stihl MS 251 is a reliable chainsaw, occasional issues may arise. Here’s a guide to troubleshooting some common problems⁚

• Engine Won’t Start⁚ Check the fuel supply, ensure the fuel lines are clear, and inspect the spark plug for fouling or damage. If the engine still won’t start, check for a clogged air filter or a faulty ignition system.
• Engine Runs Poorly⁚ A dirty air filter, a fouled spark plug, or a clogged carburetor can all contribute to poor engine performance. Clean or replace these components as needed. Also, check the fuel mixture for the correct ratio of gasoline to oil.
• Chain Doesn’t Cut Properly⁚ A dull chain, a worn or damaged bar, or improper chain tension can all affect cutting performance. Sharpen the chain, inspect the bar, and adjust the chain tension as necessary.
• Excessive Vibrations⁚ Check for loose bolts, worn bearings, or a damaged bar. Tighten loose bolts, replace worn bearings, or repair or replace a damaged bar.
• Chain Saw Overheats⁚ A clogged air filter, a dirty cooling fan, or insufficient lubrication can all lead to overheating. Clean the air filter, clean the cooling fan, and ensure adequate lubrication of the bar and chain.

If you encounter persistent problems, consult the Stihl MS 251 manual or contact a qualified service technician for assistance.

Recommended Accessories

To enhance your Stihl MS 251 experience and ensure safe and efficient operation, consider investing in these recommended accessories⁚

• Chain Sharpener⁚ Maintaining a sharp chain is crucial for smooth cutting and safety. A quality chain sharpener allows you to quickly and effectively sharpen your chain, ensuring optimal performance.
• Bar and Chain Oil⁚ Regularly lubricating the bar and chain with high-quality bar and chain oil is essential for preventing wear and tear, reducing friction, and extending the life of your cutting equipment.
• Protective Gear⁚ Safety should always be prioritized. Invest in a high-quality helmet, safety glasses, gloves, and chaps to protect yourself from potential injuries while using the chainsaw.
• Carrying Case⁚ A sturdy carrying case provides convenient storage and transportation for your chainsaw, keeping it protected from damage and elements.
• Spare Parts⁚ Having spare parts on hand, such as air filters, spark plugs, and chain, can save you time and hassle in case of unexpected issues.
• Work Gloves⁚ Gloves provide a secure grip on the chainsaw and protect your hands from cuts, scrapes, and splinters.
• Bar and Chain Gauge⁚ This tool helps ensure the correct chain tension and bar lubrication, maximizing cutting performance and extending the life of your cutting equipment.

By using these recommended accessories, you can enhance the functionality and safety of your Stihl MS 251, allowing you to tackle various cutting tasks with confidence and ease.

Where to Buy the Stihl MS 251

Finding a reliable retailer for your Stihl MS 251 is essential to ensure you get a genuine product and access to any necessary support. Here are some avenues to explore⁚

• Authorized Stihl Dealers⁚ These dealers are specifically authorized by Stihl to sell and service their products. They offer expert advice, warranty support, and access to genuine Stihl parts and accessories. Look for a local dealer using the Stihl dealer locator tool on their website.
• Online Retailers⁚ Several reputable online retailers, such as Amazon, eBay, and specialized power equipment websites, offer the Stihl MS 251. Ensure you buy from a trusted source with a good reputation for selling genuine products and providing customer service.
• Hardware Stores⁚ Many large hardware stores, such as Home Depot and Lowe’s, carry a selection of Stihl products, including the MS 251. Check with your local store to see if they have it in stock.
• Specialty Power Equipment Stores⁚ Stores that specialize in outdoor power equipment often have a wide variety of Stihl chainsaws, including the MS 251. These stores typically offer knowledgeable staff who can provide guidance and answer any questions you may have.

When making your purchase, be sure to compare prices, read customer reviews, and consider factors like warranty, shipping costs, and return policies to ensure you make the best choice for your needs.