Stihl FS250R Manual

The Stihl FS250R is a professional-grade, high-performance clearing saw designed for demanding vegetation management tasks. It features a powerful 2-stroke engine with electronic ignition, a robust gearbox, an anti-vibration system, a loop handle with throttle trigger lockout, a debris-deflecting clutch cover, and a straight shaft for use with various cutting attachments. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 2-stroke engine, electronic ignition (CDI), anti-vibration system, loop handle, straight drive shaft, gearbox, and debris-deflecting clutch cover.

Feature	Description
Engine Type	2-stroke, single cylinder, air-cooled
Ignition System	Electronic CDI
Anti-Vibration System	Reduces operator fatigue
Handle Type	Loop handle with throttle trigger lockout
Drive Shaft	Straight shaft for brush cutter and clearing saw attachments
Gearbox	Robust, grease-lubricated
Clutch Cover	Debris-deflecting design for safety
Fuel Tank Capacity	Approx. 0.95 liters (32 oz)
Powerhead Weight	Approx. 6.8 kg (15 lbs) without cutting attachment
Recommended Attachments	Brush cutter blades, clearing saw blades, polycut heads

Safety Information

Read and understand all safety warnings before operation.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, heavy-duty gloves, long pants, sturdy boots, and a hard hat with face screen.
2. Clear Work Area: Remove stones, metal, and other debris from cutting path.
3. Fuel Safety: Refuel outdoors only, with engine stopped and cool. Use clean, fresh fuel mix (50:1 gasoline to STIHL HP Ultra oil).
4. Two-Hand Operation: Always grip the saw with both hands on the handles.
5. Kickback Zone: Be aware of the danger zone at the upper quadrant of the cutting attachment.

WARNING! Failure to follow safety instructions can result in serious injury or death. Keep bystanders and pets at a safe distance.

Assembly & Preparation

Assemble the powerhead with the desired cutting attachment.

1. Attach Shaft: Align the drive shaft with the engine output shaft and secure with the provided bolts.
2. Install Handle: Position the loop handle on the shaft and tighten the clamping screws securely.
3. Install Cutting Attachment: For a blade, use the appropriate blade washer and retaining nut. Tighten counter-clockwise (left-hand thread). For a polycut head, follow the specific assembly instructions.
4. Fuel Mix: Prepare a 50:1 mix of unleaded gasoline (min. 89 octane) and STIHL HP Ultra 2-stroke oil. Fill the fuel tank.
5. Check Fasteners: Ensure all nuts, bolts, and screws are tight before starting.

CAUTION! Ensure the cutting attachment is properly installed and secured to prevent detachment during operation.

Specifications

• Engine Displacement: 41.0 cm³ (2.5 cu. in.)
• Power Output: 1.8 kW (2.4 hp)
• Idle Speed: 2,800 rpm
• Maximum Power Speed: 9,500 rpm
• Fuel/Oil Ratio: 50:1 (STIHL HP Ultra oil)
• Spark Plug: Bosch WSR 6 F or equivalent
• Gearbox Ratio: 1.27:1
• Shaft Length: Standard straight shaft
• Sound Power Level (LWA): 112 dB(A)
• Vibration Levels (ah): Left Handle: 4.5 m/s², Right Handle: 6.5 m/s²

Controls and Components

Familiarize yourself with all controls before starting.

Main Controls:

• Throttle Trigger: Located on the rear handle. Squeeze to increase engine speed.
• Throttle Trigger Lockout: Must be depressed before the throttle trigger can be engaged.
• Stop Switch: Move to the "0" or STOP position to stop the engine.
• Choke Lever/Start Assist: Used for cold starting.
• Master Control Lever (if equipped): Combines choke, stop, and run functions.
• Fuel Tank Cap: Twist to open/close. Ensure it is vented.
• Purge Bulb (Primer): Press several times before a cold start to fill the carburetor with fuel.

Starting & Stopping the Engine

Cold Start Procedure:

1. Place the unit on a firm, flat surface. Ensure the cutting attachment is clear of the ground and obstacles.
2. Press the purge bulb (primer) 5-10 times until fuel is visible.
3. Set the choke lever to the full choke position (symbol: closed butterfly).
4. Set the stop switch to the "I" or RUN position.
5. While holding the unit firmly, pull the starter rope briskly until the engine fires once (usually 1-3 pulls).
6. Move the choke lever to the half-choke or run position.
7. Pull the starter rope again to start the engine. It should start within 1-2 pulls.
8. Allow the engine to warm up at idle for 30-60 seconds before applying throttle.

Warm Start: Do not use choke. Follow steps 4, 7, and 8.

Stopping: Release the throttle trigger. Allow the engine to idle briefly. Move the stop switch to the "0" or STOP position.

Operation & Cutting Techniques

Always use a balanced, two-handed grip.

1. Swing Technique: Use a controlled, sweeping motion from right to left (for right-handed operators). Let the tool do the work; do not force it.
2. Cutting Height: Keep the cutting attachment parallel to the ground and just above the vegetation being cut.
3. Blade vs. String: Use metal blades for heavy brush, saplings, and thick weeds. Use polycut heads with nylon line for grass and light weeds.
4. Avoiding Kickback: Never engage the upper quadrant of the blade (between 12 and 3 o'clock positions) with the object being cut.
5. Slope Operation: Always stand on the uphill side of the tool. Be extremely cautious of footing.

WARNING! Never operate the tool above shoulder height or with one hand. Always be aware of your footing and balance.

Maintenance Schedule

Interval	Task
Daily / Before Use	Check all fasteners for tightness. Inspect cutting attachment for damage or wear. Check fuel level.
Every 25 Hours	Clean air filter. Check spark plug condition and gap (0.5 mm / 0.020 in).
Every 50 Hours	Clean spark arrestor screen (if equipped). Grease the gearbox (using STIHL grease).
Every 100 Hours	Replace fuel filter. Have carburetor adjustments checked by an authorized STIHL dealer.
As Needed	Sharpen or replace cutting blades. Replace worn drive shaft bearings or seals.

CAUTION! Perform maintenance only when the engine is stopped and cool. Disconnect the spark plug boot for safety during major service.

Storage

For storage periods longer than 30 days:

1. Drain the fuel tank completely and run the engine until it stops to empty the carburetor.
2. Remove the spark plug and pour about 1 teaspoon of engine oil into the cylinder. Pull the starter rope slowly 2-3 times to distribute the oil, then reinstall the spark plug.
3. Thoroughly clean the entire unit, especially the cooling fins, air filter area, and cutting attachment.
4. Store in a dry, well-ventilated place, out of reach of children. Cover the unit to keep dust out.

Warranty Information

STIHL Limited Warranty: The STIHL FS250R is backed by a limited warranty for personal or professional use. Warranty period and terms may vary by region. Proof of purchase from an authorized STIHL dealer is required. Warranty does not cover damage from misuse, neglect, improper fuel, or unauthorized modifications. For full warranty details, contact your local authorized STIHL dealer or visit www.stihlusa.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded engine, clogged air filter, faulty spark plug	Check fuel level. For flooded engine, move choke to run, hold throttle wide open, and pull starter rope. Clean/replace air filter. Check/replace spark plug.
Engine starts but dies	Dirty fuel filter, clogged fuel tank vent, carburetor issues	Replace fuel filter. Clean tank vent cap. Have carburetor serviced by a dealer.
Loss of power	Clogged air filter, dirty spark arrestor, carburetor adjustment	Clean air filter and spark arrestor screen. Have carburetor adjusted by a dealer.
Excessive vibration	Damaged or unbalanced blade, loose fasteners, bent drive shaft	Inspect and replace blade if damaged. Tighten all fasteners. Inspect shaft for damage.
Cutting attachment does not spin	Broken drive cable, worn clutch, sheared pin in gearbox	Inspect drive shaft and clutch. Have gearbox inspected by a dealer.

Service: For repairs beyond basic maintenance, contact an authorized STIHL servicing dealer. Use only genuine STIHL replacement parts.

Customer Support: STIHL Incorporated, 536 Viking Drive, Virginia Beach, VA 23452. Phone: 1-800-467-8445. Website: www.stihlusa.com