Stihl Autocut 25-2 Instruction Manual

The Stihl Autocut 25-2 is a professional-grade trimmer head designed for use with compatible Stihl brushcutters and grass trimmers. It features the AutoCut C 25-2 cutting head with a pre-wound, easy-reload nylon line system, a semi-automatic line advance mechanism (Tap 'n' Go), and is engineered for durability and efficient cutting performance in demanding conditions. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: AutoCut C 25-2 cutting head, Pre-wound spool with .095" (2.4mm) diameter nylon line, Semi-automatic line advance system (bump feed), Heavy-duty housing, and Locking mechanism for secure attachment.

Safety Information

Read and understand all instructions before use. Always wear appropriate Personal Protective Equipment (PPE).

1. PPE Required: Safety glasses, hearing protection, sturdy gloves, long pants, and boots.
2. Inspection: Inspect head, line, and machine for damage before each use.
3. Clear Area: Clear work area of bystanders, pets, and obstacles like stones or wire.
4. Operation: Keep firm footing. Do not operate near people or on unstable surfaces.
5. Hot Surfaces: The cutting head may become hot during use. Allow to cool before handling.

WARNING! Failure to follow safety instructions can result in serious injury or death. The cutting line is dangerous when rotating at high speed. Never operate without the proper cutting attachment guard (deflector) installed on the power tool.

Installation & Assembly

Ensure the power tool is turned off and the spark plug is disconnected before installation.

1. Remove Old Head: Hold drive shaft stationary and rotate the old head counterclockwise to remove.
2. Clean Threads: Clean the drive shaft threads of any debris.
3. Install AutoCut 25-2: Thread the new head onto the drive shaft by turning it clockwise. Hand-tighten firmly.
4. Secure: Use the appropriate spanner or lock the drive shaft as per your power tool's manual and tighten securely. Do not overtighten.
5. Install Guard: Ensure the correct cutting attachment guard is properly installed on the power tool.

CAUTION! Incorrect installation can cause the head to come loose during operation, creating a severe hazard. Always tighten securely.

Specifications

• Model: AutoCut C 25-2
• Line Diameter: 0.095 inch (2.4 mm)
• Line Type: High-impact nylon monofilament
• Feed System: Semi-automatic bump feed (Tap 'n' Go)
• Spool: Pre-wound, easy-reload
• Compatible Shafts: Specific Stihl models with compatible thread (e.g., M10 left-hand thread). Check operator's manual.
• Max Recommended Speed: Consult your power tool manual. Do not exceed rated RPM.
• Application: Grass, weeds, light undergrowth
• Operating Temp Range: Standard outdoor conditions. Avoid extreme cold which can make line brittle.

Controls and Operation

The primary control is the semi-automatic line advance mechanism.

Starting: Follow your power tool's starting procedure. Ensure the head is clear of the ground and obstacles.

Line Advance (Bump Feed):

1. Run the trimmer at operating speed.
2. To release more line, lightly tap ("bump") the rotating head on flat, clear ground (e.g., bare soil or hard surface).
3. The centrifugal force will release a short length of line. Repeat as needed.
4. Do not press hard or hold the head against the ground, as this wastes line and causes wear.

Stopping: Release the throttle trigger and allow the head to come to a complete stop before setting the tool down.

Loading the Cutting Line

Reload the spool when line is depleted. Use only genuine Stihl .095" (2.4mm) nylon line.

1. Stop & Cool: Ensure the tool is off and the head is cool.
2. Remove Spool: Press in the two locking tabs on the sides of the head and lift off the cover/spool assembly.
3. Remove Old Line: Discard any remaining old line from the spool.
4. Wind New Line:
   • Insert the end of the new line into the anchor hole in the spool.
   • Wind the line tightly and evenly onto the spool in the direction of the arrow marked on the spool.
   • Do not overfill. Leave enough line free to thread through the eyelets.
5. Thread Line: Pass the free ends of the line through the two opposing eyelets on the spool housing.
6. Reassemble: Place the spool back into the housing, ensuring it clicks into place. Pull on the line ends to release them from the retaining slots.

WARNING! Never use metal wire or other substitutes for nylon line. This can damage the tool and create extreme safety hazards.

Cutting Techniques

For efficient and safe trimming.

1. Sweeping Motion: Use a smooth, side-to-side sweeping motion, keeping the head parallel to the ground.
2. Cutting Arc: Utilize the tip of the line (the outer 3-4 inches) for the most effective cutting. This is where the speed is highest.
3. Avoid Hard Objects: Do not strike fences, walls, trees, or rocks with the line, as this will rapidly wear or break it.
4. Tall Grass/Weeds: Use a gradual, layered approach. Cut from the top down in sections.
5. Line Length: Maintain an optimal line length (approx. 5-6 inches beyond the guard). Excessively long line reduces power and increases wear.

Maintenance & Care

Regular maintenance ensures longevity and safe operation.

1. Daily Inspection: Check for cracks in the housing, wear on the line, and secure attachment to the drive shaft.
2. Cleaning: Remove grass, dirt, and debris from the head and guard after use. A brush or compressed air works well.
3. Spool Lubrication: Periodically apply a small amount of silicone spray to the spool post and inside the housing to ensure smooth rotation and line feed.
4. Wear Parts: Replace the entire cutting head or spool if housing is cracked, eyelets are worn, or the advance mechanism fails.

CAUTION! Perform maintenance only when the tool is completely stopped and disconnected from the power source (e.g., spark plug wire disconnected).

Storage

Store properly to prevent damage.

1. Clean the head thoroughly.
2. Store the power tool with the cutting head attached in a dry, locked place, out of reach of children.
3. If storing long-term, remove the spool and store line indoors to prevent UV degradation and moisture absorption.

Regulatory Information

This cutting attachment is designed to be used only with specific Stihl power tools as indicated in their respective instruction manuals. It complies with relevant safety standards for cutting attachments. STIHL is a registered trademark of Andreas Stihl AG & Co. KG. For genuine spare parts and accessories, contact an authorized STIHL servicing dealer. For support, visit www.stihlusa.com or contact your local STIHL dealer.

Troubleshooting

Service: For issues not resolved here, contact an authorized STIHL servicing dealer. Do not attempt to repair damaged housings or internal mechanisms.