Stihl FS 250 R Manual

The Stihl FS 250 R is a professional-grade, 2-stroke engine brushcutter/string trimmer designed for demanding clearing and maintenance work. It features a powerful engine with electronic ignition, anti-vibration system, ErgoStart™ for easier starting, a loop handle or bicycle handlebar (depending on configuration), a straight shaft with a gearbox, and compatibility with a wide range of cutting attachments. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 2-stroke engine with electronic ignition (CDI), anti-vibration system, ErgoStart™, decompression valve, straight drive shaft with gearbox, and modular design for various attachments.

Feature	Description
Engine Power	High-performance 2-stroke engine for demanding tasks
ErgoStart™	Reduces resistance in starter cord for easier starting
Anti-Vibration System	Reduces operator fatigue during extended use
Decompression Valve	Lowers compression for easier pull-starting
Straight Shaft	Durable metal drive shaft with gearbox for power transfer
Modular Design	Accepts trimmer heads, brush knives, circular saw blades
Loop Handle / Bicycle Handle	Options for different working styles and control
Throttle Trigger with Lockout	Prevents accidental throttle engagement
Fuel Tank	Integrated tank for fuel/oil mixture
Stop Switch	Immediately stops the engine

Safety Instructions

Read and understand all instructions before use. Failure to follow warnings can cause serious injury or death.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, sturdy gloves, long pants, and boots.
2. Clear Work Area: Remove stones, nails, wire, and other debris that could be thrown by the cutter.
3. Fuel Safety: Refuel outdoors, with engine off and cool. Use only STIHL-approved gasoline/oil mix.
4. Operation: Keep bystanders and pets at least 50 feet away. Hold unit firmly with both hands.
5. Kickback Zone: Be aware of the danger zone at the tip of the cutting attachment.

WARNING! Never operate the machine without proper guards and protective equipment installed. The cutting tool can cause severe lacerations.

Assembly & Preparation

Unpack and inspect contents. Assemble according to intended use (trimmer or brushcutter).

1. Handle Attachment: Secure the loop handle or bicycle handlebar to the shaft as per instructions.
2. Cutting Attachment: Install the chosen trimmer head, blade, or other tool, ensuring the guard is correctly mounted.
3. Fuel Mix: Prepare a 50:1 mixture of unleaded gasoline (min. 89 octane) and STIHL HP Ultra or equivalent high-quality 2-stroke oil.
4. Refueling: Fill the fuel tank with the prepared mixture. Wipe up any spills.

CAUTION! Ensure all fasteners are tightened to specification. An improperly assembled unit can fail and cause injury.

Specifications

• Engine Displacement: 41.0 cc (2.5 cu. in.)
• Power Output: 1.8 kW / 2.4 hp
• Fuel/Oil Ratio: 50:1 (STIHL HP Ultra oil)
• Idle Speed: 2,800 rpm
• Max. Engine Speed: 11,500 rpm (with cutting tool)
• Drive Shaft: Straight, solid metal
• Gearbox Ratio: Gear-driven for high torque
• Sound Pressure Level: Approx. 99 dB(A) - Hearing protection required.
• Vibration Levels: Left/Right Handle: < 2.5 m/s² (Front/Rear: < 5.0 m/s²)
• Weight (without cutting attachment): Approx. 6.8 kg (15.0 lbs)

Controls and Components

Familiarize yourself with all controls before starting.

Main Controls: Throttle Trigger, Throttle Trigger Lockout, Stop Switch (I/O), Choke Lever (for cold start), Decompression Valve Button, Primer Bulb (if equipped).

Components: Fuel Tank Cap, Air Filter Cover, Spark Plug, Muffler, Drive Shaft Housing, Gearbox, Attachment Mounting Flange, Cutting Attachment Guard, Harness Attachment Points (D-rings).

Adjustments: Handle position can be adjusted for operator comfort. Harness should be used to support machine weight.

Starting & Stopping the Engine

Always start on the ground in a clear area, with the cutting attachment free of obstructions.

1. Cold Start: Press fuel primer bulb (if equipped) 5x. Set choke lever to closed position (●). Press decompression valve. Hold unit securely, pull starter cord briskly until engine fires. Move choke lever to open position (○). Pull starter cord again to start.
2. Warm Start: Choke lever must be in open position (○). Pull starter cord.
3. Stopping: Release throttle trigger. Allow engine to idle briefly. Press the stop switch (O) to "0".

Tip: Do not pull starter cord to its full extent or let go of the handle; pull smoothly and allow cord to rewind.

Operation & Working Techniques

Use the correct technique to ensure safety and efficiency.

1. Carrying & Holding: Use the provided harness. Hold the handle(s) firmly with both hands.
2. Swinging Technique (Trimming): Swing the tool from right to left in a smooth, controlled arc, keeping the cutting head parallel to the ground.
3. Clearing Technique (Brush): Use a sweeping, scything motion. Let the blade do the work; do not force it.
4. Slopes: Work across the slope, not up and down. Maintain secure footing.
5. Kickback Awareness: The most dangerous area is within a 30° arc at the tip of the cutting attachment. Never let this zone contact solid objects.

WARNING! Never operate the unit above waist height. Always be aware of your surroundings and the location of the cutting tool.

Cutting Attachments

The FS 250 R is compatible with a range of STIHL attachments.

• Trimmer Heads: AutoCut C 5-2, PolyCut heads for grass and weeds.
• Metal Blades: Circular saw blades (e.g., 4-tooth, 8-tooth, 80-tooth) for brush and saplings.
• Brush Knives: 3-point or 4-point steel knives for heavy weeds.
• Clearing Blades: For heavy-duty clearing work.

Selection: Choose the attachment suitable for your task. Always use the correct guard for each attachment.

Maintenance & Storage

Regular maintenance ensures long life and safe operation. Perform maintenance with engine OFF and spark plug disconnected.

1. Daily: Clean exterior, check for loose fasteners, inspect cutting attachment for damage.
2. Air Filter: Clean regularly; replace if damaged or excessively dirty.
3. Spark Plug: Check and clean electrode gap; replace per schedule (typically 100 hrs).
4. Fuel Filter: Replace annually or as needed.
5. Gearbox Grease: Lubricate gearbox with STIHL special grease after every 25 hours of operation.
6. Storage: For long-term storage, run engine dry of fuel or add fuel stabilizer. Store in a dry, secure place.

CAUTION! Use only genuine STIHL replacement parts. Improper maintenance can void warranty and create hazards.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, spark plug faulty, switch off	Check fuel, dry spark plug, check spark, ensure stop switch is on (I).
Engine starts but dies	Clogged fuel filter, dirty air filter, carburetor adjustment	Replace fuel filter, clean air filter, have carburetor serviced by dealer.
Loss of power	Dirty air filter, clogged spark arrestor, old fuel	Clean air filter, clean spark arrestor screen, use fresh fuel mix.
Excessive vibration	Damaged cutting attachment, loose parts, bent shaft	Inspect and replace damaged blade/head, tighten all fasteners, check shaft.
Cutting attachment does not spin	Drive shaft disconnected, gearbox damaged, clutch slipping	Check shaft coupling, inspect gearbox for damage, have clutch checked by dealer.

Note: For complex repairs, contact an authorized STIHL servicing dealer.

Warranty & Service

STIHL offers a limited warranty for the FS 250 R. Proof of purchase from an authorized STIHL dealer is required.

• Warranty Period: Refer to your STIHL warranty card for specific terms and duration.
• Service: Repairs and adjustments should be performed by an authorized STIHL servicing dealer.
• Parts & Support: Use only genuine STIHL replacement parts. For dealer location or support, visit www.stihlusa.com or contact STIHL Incorporated.

Disclaimer: Specifications and information subject to change without notice. Operator is responsible for safe and proper use.