Stihl FS55 Manual: A Comprehensive Guide
This manual unveils essential details for operating and maintaining your Stihl FS55 trimmer, covering safety, assembly, fueling, starting, and troubleshooting procedures.
The Stihl FS55 is a popular, lightweight, and versatile string trimmer designed for residential use. It’s ideal for edging, trimming grass around obstacles, and maintaining lawns. This manual provides comprehensive instructions for safe operation, proper maintenance, and effective troubleshooting. Understanding its components and adhering to safety guidelines will ensure long-lasting performance and user satisfaction. Before first use, carefully review all sections to familiarize yourself with the trimmer’s features and operational procedures.
Safety Precautions
Always wear appropriate safety gear, including eye protection, hearing protection, long pants, and sturdy footwear, when operating the Stihl FS55. Keep bystanders, especially children and pets, at a safe distance. Never operate the trimmer with missing or damaged parts. Inspect the cutting head before each use. Be aware of surrounding objects and potential hazards. Avoid operating on slippery surfaces or in poor visibility.
Understanding the Components
The Stihl FS55 consists of a two-handle system, a lightweight engine, and a gearbox driving the cutting head. Key components include the throttle trigger, on/off switch, fuel tank, air filter housing, and spark plug. Cutting head options vary, offering choices like nylon line or blades; Familiarize yourself with each part’s location and function for safe operation and maintenance.
Engine Overview
The Stihl FS55 utilizes a 27.2 cc, two-stroke engine known for its reliability and fuel efficiency. It’s air-cooled, requiring regular air filter maintenance. The engine features electronic ignition for consistent starting and operation. Proper fuel mixing – specifically a 50:1 ratio of gas to oil – is crucial for longevity. Understanding these basics ensures optimal engine performance and minimizes potential issues.
Cutting Head Options
The FS55 is versatile, accepting various cutting heads. Standard is a dual-line cutting head, ideal for grass and light weeds. Optional heads include a polycut blade for tougher vegetation and a brush cutter blade for dense brush. Changing heads requires specific tools and following the manual’s instructions carefully. Selecting the correct head maximizes efficiency and safety for each task.
Assembly Instructions
Before first use, careful assembly is crucial for safe operation. This involves attaching the handle for comfortable control and securely mounting the chosen cutting head. Ensure all components click firmly into place. Double-check all fasteners are tightened according to the manual’s torque specifications. Incorrect assembly can lead to malfunctions or injury; prioritize precision during this stage.
Attaching the Handle
Proper handle attachment ensures comfortable and controlled operation of the FS55. Align the handle components with the trimmer shaft, ensuring correct orientation as illustrated in the manual. Securely fasten using the provided bolts, tightening them evenly to prevent wobbling. Verify the handle is firmly attached before proceeding, as a loose handle compromises control and safety during use.
Mounting the Cutting Head
Correctly mounting the cutting head is crucial for efficient trimming. Align the cutting head with the output shaft, ensuring the drive shaft engages fully. Rotate the head clockwise until it clicks securely into place. Double-check the locking mechanism to prevent detachment during operation. Refer to the manual’s diagrams for specific head types, ensuring compatibility and proper installation for optimal performance.
Fueling and Mixing
Proper fuel mixture is vital for the Stihl FS55’s engine longevity. Always use fresh, high-quality gasoline and Stihl 2-stroke engine oil. Incorrect ratios can cause performance issues or damage. Carefully follow the recommended fuel mix ratio detailed in the manual – typically 50:1. Thoroughly mix the fuel and oil in a clean container before adding it to the FS55’s fuel tank.
Recommended Fuel Mix Ratio
The Stihl FS55 requires a precise fuel-to-oil ratio for optimal performance and engine protection. The universally recommended ratio is 50:1. This translates to 50 parts gasoline to 1 part high-quality 2-stroke engine oil. Utilizing Stihl’s own 2-stroke oil is highly advised, ensuring compatibility and maximizing engine life. Deviating from this ratio can lead to engine damage.
Fueling Procedure
Before fueling, ensure the engine is cool and the trimmer is on a stable, level surface. Carefully remove the fuel cap, and using a funnel, slowly pour the pre-mixed fuel into the tank, avoiding spillage. Do not overfill – leave some space for expansion. Securely tighten the fuel cap after fueling. Wipe away any spilled fuel immediately before starting the engine.
Starting the FS55
Proper starting involves several key steps for reliable operation. Ensure the trimmer is on a flat surface and the choke is engaged for a cold start. Gently pull the starter cord until resistance is felt, then pull briskly. For warm starts, disengage the choke. Always hold the trimmer firmly during starting, and never start a dropped unit.
Cold Start Procedure
Initiate a cold start by ensuring the choke lever is fully engaged. Prime the carburetor by pressing the primer bulb several times until fuel is visible. Position the on/off switch to the “on” position. Firmly grasp the starter handle and pull the cord with a quick, steady motion. Repeat until the engine starts, then gradually disengage the choke.
Warm Start Procedure
For a warm start, disengage the choke lever and set the throttle to a slightly increased position. Firmly grasp the starter handle and pull the cord with a smooth, deliberate motion – avoid rapid pulls. The engine should ignite quickly. If it doesn’t, briefly engage the choke and repeat the starting process.
Operating Instructions
Always wear appropriate safety gear, including eye protection and sturdy footwear, when operating the FS55. Maintain a firm grip on the handles and keep a safe distance from obstacles. Utilize smooth, sweeping motions for efficient cutting. Regularly inspect the cutting head and line for wear, and adjust the cutting height as needed for optimal results.
Proper Cutting Techniques
Employ a side-to-side sweeping motion, allowing the line to cut the vegetation effectively. Avoid forcing the trimmer; let the rotating line do the work. Maintain a consistent walking speed and overlap each pass slightly for a clean, even cut. Be mindful of hidden objects and adjust your technique accordingly to prevent damage.
Adjusting Cutting Height
The FS55’s cutting height is primarily adjusted by the operator’s stance and the angle of the trimmer head. For lower cuts, tilt the head slightly forward while maintaining a stable grip. For higher cuts, raise the trimmer head. Practice makes perfect; experiment to find the optimal angle for various terrains and vegetation types.
Maintenance Schedule
Regular maintenance ensures optimal performance and longevity of your Stihl FS55. After each use, inspect for damage and clean debris. Every 25 operating hours, clean the air filter and check the spark plug. Annually, or after 100 hours, thoroughly inspect the gearbox for wear. Consistent upkeep prevents costly repairs and maintains cutting efficiency, extending the life of your trimmer.
Air Filter Cleaning
A clean air filter is crucial for engine performance. After every 25 hours of operation, remove the filter cover and carefully clean the filter element. Tap it gently to dislodge debris, or use compressed air – blowing from the inside out. If excessively dirty, wash in warm, soapy water, rinse, and allow to dry completely before reinstalling. A clogged filter restricts airflow, reducing power.
Spark Plug Replacement
Regular spark plug replacement ensures reliable starting and optimal engine function. Replace the spark plug after every 100 operating hours, or annually. Use only the specified spark plug type (Champion RCJ6Y or equivalent). Carefully remove the old plug with a wrench, gap the new plug to 0.08 inches, and tighten securely. Incorrect gapping or a loose plug can cause performance issues.
Troubleshooting Common Issues
Addressing issues promptly keeps your FS55 running smoothly. If the engine won’t start, check fuel levels, spark plug connection, and air filter cleanliness. Overheating often indicates a clogged air filter or improper fuel mix. A sputtering engine may need carburetor adjustment or a fresh spark plug. Always consult a qualified technician for complex repairs.
Engine Won’t Start
A non-starting engine requires systematic checks. First, ensure fresh fuel with the correct mix ratio is present. Verify the spark plug is clean, properly gapped, and securely connected. Inspect the air filter for obstructions. Confirm the choke is engaged during a cold start. If issues persist, examine the carburetor for potential blockages or malfunctions.
Overheating Problems
Consistent overheating signals potential issues needing immediate attention. A clogged air filter restricts airflow, causing the engine to run hot; Ensure adequate ventilation around the cooling fins. Check for debris accumulation near the cylinder and fan. Inspect the fuel mixture; a lean mixture can elevate temperatures. Prolonged operation under heavy load also contributes to overheating – allow for cooling breaks.
Replacing the Cutting Line
Maintaining optimal cutting performance requires timely line replacement. Always use Stihl-approved line for compatibility and safety. Determine the correct line diameter and length specified in your FS55 manual. Wind the new line onto the spool, ensuring even distribution. Properly reassemble the cutting head, securing the spool cover. Incorrect installation can lead to line jamming or premature wear, impacting cutting efficiency.
Line Diameter and Length
The Stihl FS55 typically utilizes a .080-inch diameter cutting line for general trimming tasks. Recommended line lengths vary depending on the cutting head type; consult your owner’s manual for precise specifications. Using incorrect line diameters can damage the trimmer head or reduce cutting effectiveness. Always ensure sufficient line is wound onto the spool, but avoid overfilling, which can cause malfunctions.
Line Replacement Steps
Begin by safely removing the cutting head. Clean the spool and inspect for damage before winding new line, ensuring correct direction as indicated on the head. Secure the line ends within the spool’s retaining clips. Reassemble the head, carefully guiding the line into the trimmer head’s eyelets. Finally, reattach the head to the shaft, verifying proper function before operation.
Gearbox Maintenance
Regular gearbox maintenance extends the life of your FS55. Every 50 hours, or annually, apply a lithium-based grease to the gearbox. Inspect for leaks or unusual noises during operation. Check for excessive play or wear in the gearbox components. Address any issues promptly to prevent further damage and ensure optimal performance of your Stihl trimmer.
Greasing the Gearbox
To grease the FS55 gearbox, use a lithium-based grease specifically designed for this purpose. Remove the gearbox cover and apply grease using a grease gun until fresh grease appears. Avoid overgreasing, as this can damage seals. Wipe away any excess grease. This process, performed regularly, ensures smooth operation and prevents premature wear of internal gearbox components, maximizing the trimmer’s lifespan.
Checking for Wear and Tear
Regularly inspect the gearbox for signs of wear and tear. Look for cracks in the housing, loose mounting bolts, and any unusual noises during operation. Check the drive shaft for damage or bending. If any issues are detected, discontinue use immediately and consult a qualified Stihl service technician for repair or replacement of affected parts, ensuring continued safe operation.
Storage Guidelines
Proper storage is crucial for maintaining your Stihl FS55’s longevity. Before long-term storage, thoroughly clean the unit, paying attention to the cooling fins. Drain the fuel tank completely to prevent carburetor issues. Disconnect the spark plug wire for safety. Store in a dry, secure location, away from direct sunlight and extreme temperatures, ensuring optimal performance upon retrieval.
Long-Term Storage Preparation
Preparing your Stihl FS55 for extended storage requires diligent steps. Completely empty the fuel tank and run the engine until it stalls to clear the carburetor. Clean the air filter and exterior surfaces. Apply a corrosion inhibitor to metal parts. Store the unit in a dry, dust-free environment, protected from freezing temperatures, ensuring it’s ready for use when needed.
Fuel System Considerations
The Stihl FS55 fuel system demands careful attention. Always use a fresh fuel mix with the recommended ratio of high-quality 2-stroke oil and gasoline. Avoid fuel containing ethanol, as it can damage components. Before long-term storage, completely drain the fuel tank to prevent carburetor issues and fuel line deterioration, ensuring optimal performance upon restart.
Understanding the Carburetor
The carburetor meticulously mixes air and fuel for optimal combustion. It features adjustable settings influencing idle speed and mixture richness. A clogged carburetor often causes starting difficulties or poor engine performance. Regular maintenance, including cleaning the fuel filter and carburetor jets, is crucial. Avoid disassembling the carburetor unless absolutely necessary, and consult a qualified technician for complex repairs.
Technical Specifications
The Stihl FS55 boasts a 27.2 cc displacement engine, delivering 1.0 kW (1.3 hp) of power. Its fuel tank capacity is 0.5 liters, and it utilizes a 50:1 fuel mix ratio. The trimmer weighs approximately 5.5 kg (12.1 lbs) without the cutting attachment. Sound power level reaches 101 dB(A), requiring hearing protection during operation. These specifications ensure efficient and reliable performance.
Warranty Information
Stihl offers a limited warranty on the FS55, covering defects in materials and workmanship for a specified period. Typically, this is one year from the date of purchase for homeowner use, and two years for professional use. The warranty excludes normal wear, improper maintenance, and damage from misuse. Register your product promptly to activate full warranty coverage.
Where to Find Additional Resources
For expanded support beyond this manual, visit the official Stihl website. There, you’ll discover detailed parts diagrams, frequently asked questions, and instructional videos. Authorized Stihl dealers also provide expert assistance, repairs, and genuine Stihl parts. Explore online forums dedicated to Stihl equipment for user tips and troubleshooting advice.
Frequently Asked Questions (FAQ)
Q: How often should I clean the air filter? A: Clean it after every 50 operating hours, or more frequently in dusty conditions. Q: What fuel mix ratio is recommended? A: 50:1 (gasoline and 2-stroke oil). Q: Why won’t my FS55 start? A: Check fuel, spark plug, and air filter. Q: How do I replace the cutting line? A: Follow the steps outlined in the ‘Replacing the Cutting Line’ section.
Contacting Stihl Customer Support
For immediate assistance, visit the Stihl website’s support section, offering detailed FAQs, troubleshooting guides, and downloadable manuals. Alternatively, reach their dedicated phone support team for personalized help with your FS55. Expect knowledgeable representatives ready to address your concerns. Stihl prioritizes customer satisfaction, ensuring prompt and effective solutions to any operational or maintenance questions you may encounter with your equipment.
Online Support Resources
Stihl’s official website provides a wealth of digital resources for FS55 owners. Explore comprehensive FAQs addressing common issues, detailed product manuals for download, and interactive troubleshooting guides. Access exploded diagrams to aid in parts identification and repair. Watch instructional videos demonstrating proper maintenance procedures. These online tools empower you to resolve issues independently and maximize your trimmer’s lifespan.
Phone Support Details
For direct assistance, contact Stihl customer support via phone. Trained representatives are available to address your FS55-related inquiries. Dial 1-800-GO-STIHL (1-800-467-8445) during business hours – typically Monday to Friday, 8 AM to 5 PM Eastern Time. Be prepared to provide your model number and serial number for efficient service. Expect potential wait times during peak periods, but knowledgeable support is readily available.