Safety Precautions and Guidelines
Always wear protective gear, including gloves, safety glasses, and a helmet. Ensure the chain brake is engaged when starting the engine. Avoid loose clothing and maintain a firm grip on the saw. Be aware of reactive forces and potential kickback. Use STIHL reduced kickback bars and chains as recommended. Keep bystanders at a safe distance and ensure proper ventilation in enclosed spaces.
- Never operate the saw while fatigued or under the influence of alcohol/drugs.
- Keep children and pets away from the working area.
- Regularly inspect the saw for damage or wear.
- Follow all instructions in the manual to minimize risks.
General Safety Information
Always read and understand the instruction manual before operating the STIHL MS 250 chainsaw. Use the saw only for its intended purpose and ensure all safety precautions are followed. Wear appropriate protective equipment, including safety glasses, gloves, and sturdy footwear. Ensure the chain brake is engaged when starting the engine and when not cutting. Keep loose clothing and long hair tied back to avoid entanglement. Maintain a firm grip on the saw with both hands and avoid overreaching. Operate the saw in well-ventilated areas, away from flammable materials. Be cautious of reactive forces and kickback, using STIHL-recommended low-kickback chains and bars. Never allow untrained individuals to use the saw, and keep children and pets at a safe distance. Regularly inspect the saw for damage or wear, and ensure all safety devices function properly. Follow all local safety regulations and guidelines. Refer to the manual for specific safety recommendations and operational instructions.
Reactive Forces and Kickback Prevention
Reactive forces, including kickback, are significant safety concerns when operating the STIHL MS 250. Kickback occurs when the chain tooth at the tip of the bar strikes an object, causing the saw to jerk backward. To prevent this, always use a STIHL reduced-kickback chain and bar combination, as specified in the manual. Maintain control by gripping the saw firmly with both hands, keeping your left thumb under the rear handle. Avoid cutting with the tip of the bar and ensure the chain is sharp and properly tensioned. If kickback occurs, the chain brake will automatically engage, stopping the chain within a fraction of a second. Always engage the chain brake when moving or starting the saw. Regularly inspect the chain and bar for wear or damage and replace them as needed. Proper training and awareness of reactive forces can significantly reduce the risk of injury. Always follow the manufacturer’s guidelines for minimizing kickback hazards.
Proper Protective Equipment
Wearing proper protective equipment is essential when operating the STIHL MS 250 to minimize injury risks. Always wear safety glasses or goggles to protect your eyes from debris. A helmet with a face shield or separate face protection is also recommended. Use high-quality, cut-resistant gloves to maintain a firm grip and protect your hands. Durable, chainsaw-specific pants or chaps made from materials like Kevlar® can provide excellent leg protection. Steel-toe boots with good traction are also crucial to prevent foot injuries. Avoid loose clothing that could get caught in the saw. Hearing protection, such as earplugs or earmuffs, should be worn to protect against engine noise. Ensure all protective gear meets international safety standards. Regularly inspect your equipment for wear or damage and replace it as needed. By wearing the correct protective gear, you significantly reduce the risk of injury while operating the STIHL MS 250.
Operating the STIHL MS 250
Always follow the starting procedure, engage the chain brake, and use proper cutting techniques. Ensure the saw is stopped correctly and wear protective gear during operation for safety.
Starting the Engine
To start the STIHL MS 250, ensure the chain brake is engaged and the ignition switch is in the “on” position; Prime the engine by pressing the primer bulb 4-6 times until fuel flows into the bulb. Engage the choke by moving the choke lever to the “start” position. Hold the saw firmly on the ground with the chain guard in place. Pull the starter rope slowly until resistance is felt, then pull sharply to engage the engine. Once the engine starts, move the choke lever to the “run” position and allow the engine to warm up for a few seconds before cutting. Always ensure the chain is not in contact with any material during startup to prevent accidental activation. Follow the manual’s instructions precisely for safe and efficient starting. Proper starting techniques help maintain the saw’s performance and longevity.
Engaging the Chain Brake
The chain brake on the STIHL MS 250 is a critical safety feature designed to stop the chain immediately in case of kickback or loss of control. To engage the chain brake, firmly push the brake handle forward until it clicks into place. Ensure the brake is engaged whenever the saw is not in use, during maintenance, or when moving the saw. Always check that the chain has completely stopped before approaching the saw or performing any adjustments. Proper use of the chain brake minimizes the risk of injury and ensures safe operation. Follow the manual’s guidelines for engaging and disengaging the brake to maintain optimal function and safety. Regularly inspect the brake mechanism for wear or damage to ensure reliable performance.
Stopping the Saw
To stop the STIHL MS 250 safely, first engage the chain brake by pushing the brake handle forward until it clicks. This will immediately halt the chain’s movement. Next, move the master control lever to the stop position to shut off the engine. Allow the saw to idle for a few seconds before turning it off completely. Always ensure the chain has come to a complete stop before leaving the saw unattended or performing maintenance. Regularly inspect the chain brake and master control lever for proper function and wear. Proper stopping procedures are essential for safe operation and prolonging the life of the saw. Follow the manual’s guidelines to ensure the saw stops correctly every time. This helps prevent accidents and maintains the saw’s performance. Always prioritize safety when stopping the saw, especially in hazardous environments.
Maintenance and Servicing
Regular maintenance is crucial for optimal performance. Clean or replace air filters, check chain tension, and lubricate moving parts. Sharpen the chain and ensure proper carburetor adjustment. Replace spark plugs as needed.
Sharpening and Maintaining the Chain
Sharpening and maintaining the chain is essential for optimal performance and safety. Use a file of the correct size (3/8″ or 7.5 mm) to sharpen cutters at the recommended angle (25° to 35°). Always maintain the chain’s cutting edge sharpness to prevent kickback and ensure efficient cutting. After sharpening, inspect the chain for wear or damage and replace it if necessary. Proper chain tension is critical; check and adjust it regularly to avoid over-tightening, which can damage the bar or chain. Lubricate the chain frequently with STIHL chain lube to reduce friction and prevent overheating. Clean the chain thoroughly after each use to remove dirt and debris. Regularly check the guide bar for wear and align it properly to ensure smooth operation. A well-maintained chain enhances cutting efficiency and prolongs the life of your STIHL MS 250 chainsaw.
Adjusting the Carburetor
Adjusting the carburetor on your STIHL MS 250 is crucial for optimal engine performance. Start by warming up the engine at idle for 10 minutes. Locate the adjustment screws (H and L) on the carburetor. Turn the H screw clockwise to increase the high-speed RPM or counterclockwise to decrease it. Adjust the L screw similarly for low-speed idle. Use a tachometer to ensure the idle speed is set to 2,800 ± 100 RPM and the high-speed RPM is 12,500 ± 100. Avoid over-revving the engine. If the engine runs rough or stalls, re-adjust the screws. Proper carburetor tuning ensures efficient fuel combustion, reducing emissions and improving cutting performance. Always refer to the manual for precise settings and safety guidelines.
- Use a tachometer for accurate RPM measurement.
- Avoid over-tightening or loosening the screws.
- Test the saw after adjustments to ensure smooth operation.
Replacing the Spark Plug
To replace the spark plug on your STIHL MS 250, start by allowing the engine to cool down completely. Locate the spark plug, typically found on the cylinder head. Use a spark plug wrench to remove the old plug. Inspect the area for any debris and clean it if necessary. Install the new spark plug, ensuring it is properly seated and tightened to the recommended torque specification (usually 15-20 Nm). Use a spark plug with the correct heat range as specified in the manual. Proper installation ensures reliable ignition and optimal engine performance. Always refer to the manual for exact instructions and safety precautions.
- Allow the engine to cool before starting.
- Use the correct spark plug wrench for removal.
- Ensure the spark plug is tightly secured.
