stihl fs 45 manual download

The STIHL FS 45 is a lightweight, versatile gasoline-powered string trimmer designed for residential use. It features a 2-stroke engine, a straight shaft, a loop handle, a tap-action trimmer head (AutoCut C 5-2), and a debris-deflecting shield. Below are key sections for safety, features, operation, maintenance, troubleshooting, and specifications.

Features at a Glance

Key components: 2-stroke engine, straight drive shaft, loop handle with throttle trigger and lockout, AutoCut C 5-2 trimmer head, debris shield, and muffler with spark arrestor.

Feature	Description
Engine	STIHL 2-stroke, air-cooled, single-cylinder
Powerhead	Integrated fuel tank and engine housing
Shaft	Straight, solid drive shaft
Handle	Loop handle with controls
Cutting Attachment	AutoCut C 5-2 tap-and-go trimmer head
Starter	Rewind starter with decompression valve
Throttle Trigger	With lockout to prevent accidental operation
Stop Switch	Moves to OFF/STOP position
Debris Shield	Protects operator from thrown objects
Spark Arrestor	Muffler with USDA-approved screen

Safety Information

Read and understand the manual before operation. Wear protective equipment: safety glasses, hearing protection, gloves, long pants, and sturdy boots.

1. Clear work area of bystanders, especially children and pets.
2. Inspect machine before use: check for loose parts, damage, and fuel leaks.
3. Use the right fuel: mix high-quality 2-stroke oil with unleaded gasoline (50:1 ratio for STIHL oil).
4. Operate with both hands, firm footing, and good balance.

WARNING! Risk of fire, kickback, and thrown objects. Never operate without proper guard. Do not smoke near fuel.

Assembly & First Use

Unpack and assemble according to instructions.

1. Attach handle: Align and secure with screws.
2. Install debris shield: Slide onto shaft and secure.
3. Attach cutting head: Thread AutoCut head onto drive shaft (right-hand thread).
4. Add fuel: Use approved fuel mix in clean fuel tank.
5. Start engine: Place on ground, set choke, pull starter cord.

CAUTION! Ensure all fasteners are tight. Start the engine at least 10 feet from fueling spot.

Specifications

• Engine Displacement: 27.2 cc (1.7 cu. in.)
• Power Output: 0.8 kW (1.1 hp)
• Fuel Tank Volume: 0.42 L (14.2 fl. oz.)
• Weight (powerhead): 5.0 kg (11.0 lbs)
• Shaft Length: Straight shaft design
• Cutting Swath: Approx. 42 cm (16.5 in) with trimmer head
• Sound Pressure: Typically 94 dB(A)
• Vibration Levels: Left/Right handle: < 2.5 m/s²
• Warranty: Limited warranty, see manual for terms.

Controls & Operation

Handle: Throttle trigger with lockout, stop switch. Starting: Use choke for cold start.

Operation: Hold trimmer with right hand on throttle handle, left hand on shaft. Swing trimmer in arc, cutting with tip of line. Avoid pushing head into ground.

Stopping: Release throttle, move stop switch to OFF. Transport: Ensure engine is off and cool.

Fuel & Lubrication

Use fresh, unleaded gasoline (min. 89 octane) mixed with STIHL 2-stroke oil (50:1). For other oils, follow oil manufacturer's mix ratio (e.g., 50:1).

1. Mix fuel in clean, approved container.
2. Fill fuel tank on level surface, avoid spills.
3. Lubricate gearbox periodically with STIHL grease.

Tip: Never use fuel older than 30 days. Do not mix oil directly in fuel tank.

Maintenance & Cleaning

Perform daily and periodic maintenance. Always stop engine and disconnect spark plug boot.

1. Air filter: Clean regularly; replace if damaged.
2. Spark plug: Check gap (0.020 in / 0.5 mm); replace if worn.
3. Fuel filter: Replace annually or if clogged.
4. Exterior: Clean with damp cloth; remove debris from cooling fins and shield.
5. Carburetor adjustment: Only by authorized STIHL dealer.

WARNING! Use only STIHL replacement parts. Never run engine without air filter.

Cutting Attachment

AutoCut C 5-2 head: Tap on ground (at operating speed) to advance trimmer line.

1. Installing line: Use .095 in (2.4 mm) diameter round nylon line.
2. Wind line onto spool in direction of arrow.
3. Thread ends through eyelets.
4. Cut line to length (approx. 6 in / 15 cm).
5. Replace spool when line is worn.

CAUTION! Do not use metal blades or other attachments not approved by STIHL for this model.

Storage

For storage longer than 30 days:

1. Drain fuel tank and run carburetor dry.
2. Remove spark plug, add a few drops of oil, pull starter slowly, reinstall plug.
3. Clean entire unit and store in dry, secure place.
4. Protect from dust and moisture.

CAUTION! Fuel left in tank can degrade and damage fuel system.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, spark plug	Check fuel; set choke to off; dry plug; check spark.
Engine runs poorly	Dirty air filter, old fuel	Clean/replace filter; use fresh fuel mix.
Line does not advance	Worn line, tangled spool	Tap head firmly; reload spool correctly.
Excessive vibration	Damaged cutting head, loose parts	Inspect head; tighten all fasteners.
Loss of power	Clogged fuel filter, muffler screen	Replace fuel filter; clean spark arrestor screen.

Service: For repairs, contact authorized STIHL servicing dealer.

Warranty & Support

STIHL Limited Warranty: Covers defects in materials/workmanship. Proof of purchase required. Does not cover normal wear, misuse, or improper maintenance. For the full warranty text, see the separate warranty document included with your product.

For technical support, parts, or to locate a dealer: Visit www.stihlusa.com or call 1-800-467-8445.