Stihl HS45 Hedge Trimmer Manual

The Stihl HS45 is a lightweight, professional-grade petrol hedge trimmer featuring a powerful 27.2cc engine, double-sided cutting blades with 600mm (24") cutting length, 26mm tooth spacing, anti-vibration system, easy-start technology, ErgoStart, and a translucent fuel tank. Below are key sections for safety, features, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 27.2cc petrol engine, double-sided cutting blades, anti-vibration handles, ErgoStart system, translucent fuel tank, and tool-free air filter access.

Feature	Description
Engine	27.2cc STIHL 2-MIX engine, reduced emissions
Cutting Length	600mm (24 inches)
Tooth Spacing	26mm
Weight	Approx. 5.2 kg (11.5 lbs)
Anti-Vibration	Integrated system in handles
Starting System	ErgoStart for easier pull starts
Fuel Tank	Translucent for easy fuel level check
Blade Type	Double-sided, laser-cut steel
Throttle Lock	Prevents accidental throttle engagement
Air Filter	Tool-free access for easy cleaning

Safety Instructions

Read all instructions before use. Wear appropriate PPE.

1. Always wear safety glasses, hearing protection, gloves, and sturdy footwear.
2. Inspect the trimmer and area before each use. Remove debris and obstacles.
3. Keep bystanders, especially children and pets, at a safe distance.
4. Never operate with damaged or loose parts. Ensure all guards are in place.
5. Use both hands to operate the trimmer. Maintain secure footing.

WARNING! Petrol is flammable. Refuel in a well-ventilated area with the engine off and cool. Do not smoke.

Assembly & Preparation

Unpack and inspect contents. Assemble handle and cutting blade guard.

1. Attach the handle: Align with mounting points and secure with provided bolts.
2. Install the blade guard: Slide onto the blade when not in use for safe storage.
3. Fuel mix: Use STIHL MotoMix or mix high-quality 2-stroke oil with unleaded petrol (50:1 ratio).
4. Fill fuel tank: Use a clean funnel. Do not overfill.
5. Check oil: The gearbox is lubricated at the factory; check for leaks before use.

CAUTION! Ensure all fasteners are tight before starting the engine.

Technical Specifications

• Model: HS45
• Engine Power: 27.2cc, 0.9 kW (1.2 bhp)
• Cutting Length: 600mm (24")
• Tooth Spacing: 26mm
• Weight (without fuel): 5.2 kg (11.5 lbs)
• Fuel Tank Capacity: 0.55 litres
• Oil Tank Capacity (Gearbox): 0.1 litres
• Sound Pressure Level: 96 dB(A)
• Vibration Level (left/right): 4.5/5.5 m/s²
• Emissions Compliance: EPA Phase II, EU Stage II

Controls and Components

Main components: Throttle trigger, throttle lockout, stop switch, choke lever, primer bulb, fuel tank cap, and air filter cover.

Handle Area: Throttle trigger, throttle lockout (must be pressed to engage throttle), stop switch (I=Run, 0=Stop).

Engine Area: Choke lever (for cold starts), primer bulb (press 5-10 times for cold starts), air filter cover (tool-free clips), spark plug cover.

Cutting Head: Double-sided blades, blade bolt for tension adjustment, gearbox housing.

Starting & Stopping

Starting (Cold Engine):

1. Place trimmer on a flat, clear surface.
2. Press the fuel primer bulb 5-10 times.
3. Move the choke lever to the closed position (up).
4. Press the throttle lockout and squeeze the throttle trigger once, then release.
5. Pull the starter rope briskly until the engine fires (may take several pulls).
6. Immediately move the choke lever to the open position (down).
7. Pull the starter rope again to start the engine. Allow to warm up at idle for 30 seconds.

Starting (Warm Engine): Do not use choke. Follow steps 4 and 7.

Stopping: Release the throttle trigger and press the stop switch to "0".

Operating Instructions

Hold the trimmer with both hands. Use a smooth, sweeping motion.

1. Grip: Hold the front handle with your left hand and the rear handle with your right hand.
2. Stance: Stand with feet shoulder-width apart for balance.
3. Cutting Technique: Use the full length of the blade in a slow, arcing motion. Avoid forcing the blades.
4. Direction: Cut from the bottom of the hedge upwards for best debris fall.
5. Top Cutting: Keep the blade flat for a level top.
6. Maintain Speed: Keep the engine at full throttle during cutting for optimal blade speed.

Tip: Periodically clean blade sap and debris with a stiff brush (engine off).

Maintenance & Cleaning

Perform maintenance with the engine off and cool. Use STIHL genuine parts.

Daily/Before Use: Check for loose fasteners, inspect blades for damage, clean air filter, check fuel level.

Air Filter: Remove cover, tap out debris, or wash in warm soapy water if very dirty. Dry completely before reinstalling.

Blade Care: Clean with a brush and apply STIHL blade lubricant or light machine oil to reduce friction and rust.

Spark Plug: Check and clean every 50 operating hours. Replace if electrodes are worn. Gap: 0.5mm.

Fuel Filter: Replace every season or if fuel flow is restricted.

Gearbox Lubrication: Check grease level annually or as needed. Use STIHL special grease.

Storage

For storage longer than 30 days, prepare the engine to prevent fuel system issues.

1. Drain all fuel from the tank and carburetor by running the engine until it stops.
2. Remove spark plug and add a teaspoon of engine oil into the cylinder. Pull starter rope slowly to distribute, then reinstall plug.
3. Thoroughly clean the entire trimmer, especially the cutting blades. Apply oil to blades.
4. Store in a dry, secure place, out of reach of children, with the blade guard installed.

CAUTION! Never store with fuel in the tank for extended periods. Use fuel stabilizer if you must store with fuel.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, flooded, spark plug	Check fuel; if flooded, move choke to open and pull starter with throttle open; check/replace spark plug.
Engine runs poorly/stalls	Dirty air filter, old fuel	Clean/replace air filter; drain and refill with fresh fuel mix.
Excessive vibration	Loose blade or mounting bolts	Stop engine. Check and tighten all blade and mounting bolts.
Blades jam or cut poorly	Dull blades, debris, loose tension	Clean blades; sharpen or replace if dull; check blade bolt tension.
Loss of power	Clogged fuel filter, exhaust screen	Replace fuel filter; clean spark arrestor screen in muffler (engine cool).

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

Warranty & Support

STIHL Limited Warranty: Refer to your STIHL warranty card for specific terms and duration. Proof of purchase from an authorized STIHL dealer is required. For service, always use an authorized STIHL servicing dealer to maintain warranty coverage. For support, locate your nearest dealer at www.stihl.com or contact STIHL customer service.

Service: Authorized STIHL Dealers Only.

Support Website: www.stihl.com