Stihl Supercut 20 2 Manual

The Stihl Supercut 20 2 is a professional-grade brush cutter and grass trimmer designed for demanding clearing and maintenance work. It features a powerful 2-stroke engine, the STIHL Polycut 20-2 cutting head, a lightweight yet robust shaft, anti-vibration system, and ergonomic controls. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Assembly & Preparation 3. First-Time Operation 4. Specifications 5. Controls and Functions 6. Cutting Attachments 7. Operation & Techniques 8. Safety Features 9. Maintenance & Storage 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: 2-stroke engine, STIHL Polycut 20-2 cutting head, Ergonomic handle with controls, Anti-vibration system, Fuel tank, and Quick-stop inertia chain brake.

Feature	Description
Engine	Powerful 2-stroke engine with electronic ignition
Cutting Head	STIHL Polycut 20-2 for nylon line trimming
Shaft	Lightweight, robust composite shaft
Anti-Vibration	Integrated system to reduce operator fatigue
Handle	Ergonomic loop handle with throttle trigger and lockout
Fuel System	Transparent tank with fuel level indicator
Starter	Easy-start system with decompression valve
Safety	Quick-stop inertia chain brake (if equipped with blade)
Weight	Lightweight design for easy handling
Air Filtration	Pre-cleaning system for extended engine life

Assembly & Preparation

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

Attach the shaft: Connect the drive shaft to the engine unit, ensuring it clicks securely into place.
Install the handle: Slide the loop handle onto the shaft and tighten the clamping screws.
Fit the cutting attachment: For the Polycut head, follow the specific threading instructions. For metal blades, ensure the blade carrier is correctly mounted and the retaining nut is securely tightened with the appropriate tool.
Add fuel and oil: Use STIHL MotoMix pre-mixed fuel or mix STIHL 2-stroke engine oil with unleaded gasoline at a 50:1 ratio. Fill the fuel tank.

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

First-Time Operation

Before starting, perform a safety check of the machine and surrounding area.

Starting the engine: Place the unit on a firm, flat surface. Set the master control lever to the cold start position (choke on). Press the fuel pump bulb several times. Pull the starter rope smoothly until the engine fires, then move the master control to the run position and pull again to start.
Warm-up: Allow the engine to run at idle for a short period to reach operating temperature.
Engaging the cutting tool: With the engine at idle, press and hold the throttle trigger lockout, then squeeze the throttle trigger to increase engine speed. The cutting head or blade will begin to rotate.
Basic operation: Use a smooth, sweeping motion from right to left, keeping the cutting head parallel to the ground.

CAUTION! Never operate the machine without proper PPE. Keep bystanders and pets at a safe distance.

Specifications

Engine Type: STIHL 2-stroke, single cylinder.
Displacement: [e.g., 21.2 cc] (Refer to specific model plate).
Power Output: [e.g., 0.8 kW] (Refer to specific model plate).
Fuel/Oil Mix: 50:1 (STIHL 2-stroke oil with unleaded gasoline) or use STIHL MotoMix.
Fuel Tank Capacity: [e.g., 0.35 liters].
Sound Power Level: Complies with relevant directives (see rating label).
Vibration Levels: Front/Rear handle values per test standards.
Cutting Equipment: STIHL Polycut 20-2 head (standard), compatible with various STIHL trimmer heads and blades.
Shaft:Straight, solid drive shaft.
Weight (without cutting attachment): [e.g., 4.6 kg].

Controls and Functions

Master Control Lever: Combines stop switch, choke, and run positions. Throttle Trigger: Controls engine speed. Throttle Trigger Lockout: Must be depressed to engage throttle. Handle: Loop design with vibration damping. Quick-stop Inertia Chain Brake: Located on the handle (if equipped); designed to stop the cutting blade rapidly in a kickback event.

Starting Procedure: Master control to cold start, press fuel pump, pull starter. Move to run position after engine fires.

Stopping: Move master control lever to the STOP position.

Cutting Attachments

Primary: STIHL Polycut 20-2 head for nylon line. Options: Various STIHL trimmer heads, circular grass blades, and brush knives.

Always ensure the engine is OFF and spark plug boot disconnected before changing attachments.

Use only STIHL-approved cutting attachments and mounting hardware.

For blade installation, use the correct wrench to secure the retaining nut. Ensure the blade carrier and any washers are correctly oriented.

Check cutting attachment for damage or excessive wear before each use.

Tip: For the Polycut head, tap the head on the ground (with engine off) to advance fresh line. Never "bump" while the engine is running.

Operation & Techniques

Designed for trimming grass, weeds, and light brush.

Stance: Stand firmly with feet shoulder-width apart. Hold the unit with both hands.

Swing: Use your hips to swing the tool in a controlled arc, keeping the cutting head/blade parallel to the ground. Cut from right to left for best debris discharge.

Line Length: For the Polycut head, keep the nylon line at the recommended length. Excessive line length reduces power and increases wear.

Avoiding Hazards: Never operate near fences, rocks, or hard objects that could damage the tool or cause line breakage/kickback. Be aware of hidden wires or stones.

Slopes: Operate across the face of slopes, not up and down. Maintain secure footing.

WARNING! The cutting tool continues to rotate after the throttle is released. Allow it to come to a complete stop before setting the machine down. Be alert for kickback, especially when using metal blades.

Safety Features

Quick-stop Inertia Chain Brake: Stops the cutting blade within seconds if activated by a sudden upward movement (kickback). Throttle Trigger Lockout: Prevents accidental throttle engagement. Muffler with Spark Arresting Screen: Helps prevent ignition of dry vegetation. Decompression Valve: Reduces pulling force required for starting.

Maintenance & Storage

Perform daily maintenance checks. Always disconnect the spark plug boot before servicing.

Daily: Clean the exterior, check for loose fasteners, inspect the cutting attachment for damage, check the air filter and clean if necessary.

Periodic: Clean the spark arrestor screen (muffler), replace the spark plug, clean the fuel filter, and check the drive shaft lubrication.

Storage: For long-term storage, run the engine until the carburetor is empty of fuel or add fuel stabilizer. Clean the entire machine thoroughly. Store in a dry, secure place, out of reach of children.

CAUTION! Use only genuine STIHL replacement parts. Improper maintenance can lead to unsafe operation and void the warranty.

Regulatory Information

This product complies with relevant machinery, electromagnetic compatibility, and noise emission directives. It features a CE mark. The engine meets applicable exhaust emission regulations. STIHL and Supercut are registered trademarks of ANDREAS STIHL AG & Co. KG. For genuine parts, accessories, and service, contact an authorized STIHL servicing dealer.

Troubleshooting

Symptom Possible Cause Corrective Action

Engine will not start No fuel, flooded, spark plug faulty, switch off Check fuel level; wait if flooded; check/clean/replace spark plug; ensure master control is in start position.

Engine starts then dies Clogged fuel filter, dirty air filter, carburetor issues Replace fuel filter; clean air filter; have carburetor serviced by dealer.

Loss of power Dirty air filter, clogged spark arrestor, old fuel Clean air filter and spark arrestor screen; use fresh, properly mixed fuel.

Excessive vibration Damaged cutting attachment, loose parts, bent shaft Inspect and replace damaged blade/head; tighten all fasteners; inspect shaft.

Cutting head does not turn Drive shaft disconnected, clutch worn Check shaft connection; have clutch inspected by dealer.

Line does not advance Empty line spool, line tangled, worn head Refill spool; clear tangles; replace head if worn.

Service: For repairs beyond basic maintenance, contact your authorized STIHL dealer. Use only STIHL original parts.

Support: Consult your STIHL dealer or visit www.stihl.com for more information.

Stihl Supercut 20 2 Manual © - All Rights Reserved 2025

Symptom	Possible Cause	Corrective Action
Engine will not start	No fuel, flooded, spark plug faulty, switch off	Check fuel level; wait if flooded; check/clean/replace spark plug; ensure master control is in start position.
Engine starts then dies	Clogged fuel filter, dirty air filter, carburetor issues	Replace fuel filter; clean air filter; have carburetor serviced by dealer.
Loss of power	Dirty air filter, clogged spark arrestor, old fuel	Clean air filter and spark arrestor screen; use fresh, properly mixed fuel.
Excessive vibration	Damaged cutting attachment, loose parts, bent shaft	Inspect and replace damaged blade/head; tighten all fasteners; inspect shaft.
Cutting head does not turn	Drive shaft disconnected, clutch worn	Check shaft connection; have clutch inspected by dealer.
Line does not advance	Empty line spool, line tangled, worn head	Refill spool; clear tangles; replace head if worn.