Stihl HL 100 Service Manual

The Stihl HL 100 is a professional-grade hedge trimmer designed for demanding trimming and shaping tasks. This manual provides essential information for safe operation, routine maintenance, troubleshooting, and repair procedures to ensure optimal performance and longevity of your tool. Below are key sections covering safety, specifications, operation, maintenance, and troubleshooting.

Safety Instructions

Always read and understand the manual before use. Wear appropriate personal protective equipment (PPE).

Hazard	Precaution
Kickback	Keep cutting blade away from hard objects; maintain firm grip.
Flying Debris	Wear safety glasses, gloves, long pants, and sturdy boots.
Fuel Handling	Refuel in well-ventilated area with engine off and cool.
Hot Surfaces	Avoid contact with muffler and cylinder during/after operation.
Electrical Hazards	Keep away from power lines; do not operate in wet conditions.
Noise Exposure	Wear hearing protection during extended use.
Vibration	Take regular breaks to minimize hand-arm vibration syndrome.

WARNING! Failure to follow safety instructions can result in serious injury or death. Never operate a damaged or improperly adjusted tool.

Technical Specifications

• Model: HL 100
• Engine Type: 2-stroke, single-cylinder, air-cooled
• Displacement: 25.4 cm³ (1.55 cu in)
• Power Output: 0.8 kW (1.1 hp)
• Fuel/Oil Mix: 50:1 (Stihl HP Ultra or equivalent)
• Fuel Tank Capacity: 0.5 L (16.9 fl oz)
• Cutting Blade Length: 60 cm (24 in)
• Tooth Spacing: 20 mm (0.79 in)
• Weight (dry): 5.2 kg (11.5 lbs)
• Sound Pressure Level: 94 dB(A)
• Vibration Level: 5.2 m/s² (left/right handle)

Component Overview

Key components: Throttle trigger with lockout, Stop switch, Choke lever, Primer bulb, Fuel tank cap, Air filter cover, Spark plug, Muffler, Cutting blade, Blade guard, Handle assembly, Decompression valve.

Component	Description
Throttle Trigger	Controls engine speed; includes lockout to prevent accidental activation.
Stop Switch	Moves to STOP position to shut off engine.
Choke Lever	Used for cold starting (position I or II).
Primer Bulb	Pumps fuel into carburetor for easier starting.
Cutting Blade	Double-sided reciprocating blade with hardened steel teeth.
Blade Guard	Protective cover for safe storage and transport.
Decompression Valve	Reduces compression for easier pull-starting.

Assembly & Initial Setup

Unpack all parts. Inspect for shipping damage.

1. Attach handle: Align with mounting points and secure with provided bolts.
2. Install blade guard: Slide onto blade when not in use.
3. Fuel mix: Prepare 50:1 mix with unleaded gasoline (min. 89 octane) and Stihl 2-stroke oil.
4. Fill fuel tank: Use clean funnel; avoid spills. Tighten cap securely.
5. Check all fasteners: Ensure all nuts, bolts, and screws are tight.

CAUTION! Use only Stihl-approved replacement parts. Incorrect assembly can lead to tool failure.

Operation Guidelines

Starting procedure: Place on flat, clear surface. Engage blade guard.

1. Cold start: Set stop switch to I, choke lever to II, press primer bulb 5-10 times.
2. Pull starter rope briskly until engine fires. Move choke lever to I.
3. Pull starter rope again to start engine. Allow 30-second warm-up at idle.
4. Operating: Squeeze throttle trigger lockout and throttle to increase speed.
5. Cutting technique: Use smooth, sweeping motions; avoid forcing blade.
6. Stopping: Release throttle, allow idle, move stop switch to STOP.

Tip: Never operate at full throttle without load for more than 10 seconds.

Fuel & Lubrication

Use fresh, unleaded gasoline (max. 10% ethanol). Mix with Stihl HP Ultra oil at 50:1 ratio.

• Fuel Mix: 2.6 oz oil per 1 gallon gasoline (or 20 ml per 1 liter).
• Chain Oil: Lubricate blade rail daily with Stihl hedge trimmer oil.
• Gearbox Grease: Check and replenish every 50 operating hours.

WARNING! Do not use automotive oil, dirty fuel, or fuel older than 30 days. Store fuel in approved container.

Routine Maintenance

Perform maintenance with engine off and cool. Disconnect spark plug wire.

Interval	Task
Daily	Clean air filter; check blade for damage; tighten fasteners.
Every 25 hrs	Replace spark plug; clean cooling fins; inspect fuel filter.
Every 50 hrs	Clean carburetor; check fuel lines; grease gearbox.
Every 100 hrs	Decarbonize exhaust port and muffler; check clutch.

Note: Maintenance intervals may vary based on operating conditions.

Cutting Blade Care

Keep blade sharp and clean for optimal performance and reduced vibration.

1. Cleaning: Remove sap and debris with resin solvent after each use.
2. Sharpening: Use flat file to sharpen teeth at original angle (approx. 30°).
3. Lubrication: Apply oil to blade rail before and during operation.
4. Inspection: Check for cracks, bent teeth, or excessive wear.
5. Replacement: Replace blade if damaged or teeth are worn beyond repair.

CAUTION! Always wear heavy gloves when handling cutting blade.

Carburetor Adjustment

Adjust only if engine runs poorly. Use Stihl adjustment tool.

1. Idle speed (LA): Turn clockwise to increase, counterclockwise to decrease. Set so blade does not move at idle.
2. Low-speed mixture (L): Turn clockwise until engine runs smoothly at low throttle.
3. High-speed mixture (H): Adjust for maximum power without overheating (typically 1 turn open from seated).
4. Final check: Engine should accelerate smoothly without hesitation.

Note: Default factory settings are often optimal. Only adjust if necessary.

Spark Plug Service

Recommended plug: Bosch WSR6F or NGK BPMR7A. Gap: 0.5 mm (0.020 in).

1. Remove spark plug cap and clean area.
2. Use socket wrench to remove plug.
3. Inspect electrode: Replace if worn, fouled, or cracked.
4. Set gap with feeler gauge; adjust side electrode if needed.
5. Reinstall plug hand-tight, then tighten 1/4 turn with wrench.
6. Reattach cap securely.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, flooded, bad spark plug	Check fuel; dry plug; replace spark plug.
Engine runs poorly	Dirty air filter, clogged fuel filter	Clean/replace air filter; replace fuel filter.
Excessive vibration	Loose fasteners, dull/bent blade	Tighten all bolts; sharpen or replace blade.
Blade doesn't move	Broken clutch spring, gearbox issue	Inspect clutch; check gearbox for damage.
Overheating	Dirty cooling fins, lean fuel mixture	Clean fins; adjust carburetor (richen mixture).
High fuel consumption	Carburetor adjustment, air leak	Adjust H needle; check crankcase seals.

Reset: For electronic ignition issues, disconnect spark plug wire for 1 minute.

Service: For complex repairs, contact authorized Stihl servicing dealer.

Storage

Prepare tool for storage if not used for more than 30 days.

1. Drain fuel tank and run engine until it stops to empty carburetor.
2. Remove spark plug, add 1 tsp of engine oil into cylinder, pull starter slowly 2-3 times, reinstall plug.
3. Clean entire tool thoroughly, especially cooling fins and air filter.
4. Apply light oil to cutting blade to prevent rust.
5. Store in dry, secure location, away from children, with blade guard installed.

CAUTION! Never store with fuel in tank for extended periods; fuel degrades and can damage engine.