Manual for Stihl FS72

The Stihl FS72 is a lightweight, professional-grade string trimmer designed for demanding clearing and trimming tasks. It features a powerful 2-stroke engine, a robust drive system, an adjustable loop handle, and a tap-and-go cutting head. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 2-stroke engine, Loop handle, Drive shaft, Tap-and-go cutting head, Throttle trigger, Stop switch, Fuel tank, Primer bulb.

Feature	Description
Engine	Powerful 2-stroke engine with electronic ignition
Handle	Adjustable loop handle with vibration damping
Drive System	Robust drive shaft for reliable power transmission
Cutting Head	Tap-and-go head for easy line advancement
Throttle Trigger	With throttle trigger lockout for safety
Stop Switch	Easy-access stop switch
Fuel Tank	Integrated, translucent for fuel level check
Primer Bulb	For easy cold starting
Spark Arrestor	Muffler with integrated spark arrestor screen
Carrying System	Compatible with STIHL harnesses

Assembly & Preparation

Unpack and inspect all parts. Assemble on a clean, flat surface.

1. Attach the handle: Align with mounting points and secure with provided bolts.
2. Install the cutting attachment: Ensure the drive shaft is clean. Attach the guard, then the cutting head, tightening securely with the appropriate tool.
3. Fuel mix: Prepare a 50:1 mixture of high-quality 2-stroke engine oil and unleaded gasoline (min. 89 octane). Fill the fuel tank.
4. Check all fasteners: Ensure all nuts, bolts, and screws are tight before operation.

WARNING! Always wear appropriate personal protective equipment (PPE) including eye protection, hearing protection, gloves, long pants, and sturdy boots.

Starting & Operation

Follow the cold start procedure for a safe and reliable start.

1. Place the unit on a firm, flat surface. Ensure the cutting attachment is clear of obstacles.
2. Press the fuel pump (primer) bulb 5-10 times until fuel is visible.
3. Set the master control lever to the cold start position (choke).
4. Hold the unit firmly. Pull the starter rope briskly until the engine fires (usually 2-5 pulls).
5. Immediately move the master control lever to the warm start/half-throttle position.
6. Pull the starter rope again to start the engine. Allow to idle for 10-15 seconds to warm up.
7. To operate: Squeeze the throttle trigger lockout and the throttle trigger simultaneously. Use a smooth, sweeping motion for trimming.

CAUTION! Never start the engine indoors or in poorly ventilated areas. Exhaust gases are poisonous.

Specifications

• Engine Type: STIHL 2-stroke, single cylinder.
• Displacement: [e.g., 27.2 cc] (Refer to specific unit data plate).
• Power Output: [e.g., 0.9 kW / 1.2 bhp].
• Fuel/Oil Ratio: 50:1 (High-quality 2-stroke oil).
• Fuel Tank Volume: [e.g., 0.53 liters].
• Sound Pressure Level: Approx. [e.g., 96 dB(A)] - Wear hearing protection.
• Vibration Level: Front/Rear handle: [e.g., 4.5/2.5 m/s²].
• Cutting Swath: Depends on cutting attachment (e.g., line head ~430mm).
• Weight (without cutting attachment): Approx. [e.g., 5.2 kg].

Controls & Adjustments

Master Control Lever: Combines stop switch, choke, and run positions. Throttle Trigger: With integrated lockout for safety. Throttle Cable: Adjustable for precise control.

Handle Adjustment: Loosen mounting bolts, rotate handle to desired position, re-tighten securely.

Drive Shaft Greasing: Lubricate periodically with STIHL special grease cartridge.

Idle Speed Adjustment: Should only be performed by authorized STIHL servicing dealers.

Cutting Attachments

Compatible with various STIHL trimmer heads and blades.

1. Tap-and-Go Trimmer Head: Tap head on ground (at high idle) to advance cutting line.
2. Blades: Use only STIHL-approved metal or polycut blades for heavy vegetation.
3. Installation: Ensure engine is OFF and spark plug boot is disconnected. Use the appropriate spanner to secure the attachment.
4. Guard: Always use the correct cutting attachment guard. It is a critical safety device.

Tip: Use the correct line diameter and type for your trimmer head as specified in the manual.

Maintenance Schedule

Supports long life with regular maintenance.

1. Before each use: Check for loose fasteners, damaged parts, and fuel leaks. Inspect cutting attachment.
2. Daily/Air Filter: Clean pre-filter and main filter. Replace if damaged or excessively dirty.
3. Spark Plug: Check and clean electrode gap periodically. Replace annually or as needed.
4. Fuel Filter: Replace once per season or if clogged.
5. Gear Housing: Check for grass/debris buildup and clean. Grease gearbox as per manual.
6. Exhaust System/Spark Arrestor: Clean screen regularly to prevent overheating (when engine is cold).
7. Drive Shaft: Lubricate with special grease every 25 hours of operation.

WARNING! Perform maintenance only when the engine is OFF and cool. Disconnect the spark plug boot.

Safety Features

Throttle Trigger Lockout: Prevents accidental throttle engagement. Stop Switch: Immediately stops the engine. Cutting Attachment Guard: Shields operator from debris and the cutting tool. Vibration Damping System: Reduces operator fatigue.

Care & Storage

For long-term storage (over 30 days): 1. Drain the fuel tank and run the carburetor dry. 2. Remove spark plug, add a few drops of oil into the cylinder, pull starter rope slowly to distribute, reinstall plug. 3. Clean the entire unit thoroughly. 4. Store in a dry, dust-free, and secure place, out of reach of children.

CAUTION! Never store the unit with fuel in the tank indoors. Fuel vapors are flammable and explosive.

Regulatory Information

This product complies with relevant machinery directives and emission standards. It features an EPA/CARB certified engine. The muffler contains a USDA approved spark arrestor. STIHL is a registered trademark. For genuine parts, accessories, and service, contact an authorized STIHL servicing dealer. For support, visit www.stihlusa.com or contact customer service.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, spark plug	Check fuel mix; follow flooded start procedure; check/clean/replace spark plug.
Engine starts then dies	Clogged fuel filter, air filter, carburetor	Replace fuel filter; clean air filter; have carburetor serviced by dealer.
Loss of power	Dirty air filter, clogged spark arrestor, old fuel	Clean/replace air filter; clean spark arrestor screen; use fresh fuel mix.
Excessive vibration	Damaged cutting attachment, loose parts, bent drive shaft	Inspect and replace damaged head/blade; tighten all fasteners; inspect shaft.
Line not advancing	Empty spool, tangled line, worn head	Refill spool with correct line; untangle or replace line; replace head if worn.

Dealer Service: For repairs beyond basic maintenance, contact your authorized STIHL servicing dealer.

Support: www.stihlusa.com - Find your local dealer for parts and service.