Stihl Autocut 25-2 Manual

The Stihl Autocut 25-2 is a professional-grade trimmer head designed for use with compatible Stihl brushcutters and trimmers. It features a semi-automatic line advance system, a 25-foot capacity of 0.095-inch (2.4mm) diameter trimmer line, a robust cutting blade for clean cuts, and a durable polycarbonate housing. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Polycarbonate cutting head, semi-automatic bump-feed mechanism, pre-wound spool with 25 ft of line, cutting blade, and mounting hardware.

Safety Instructions

Always read and understand the brushcutter's manual before installing or operating the Autocut head.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, long pants, sturdy boots, and gloves.
2. Pre-Operation Check: Inspect the head for cracks, wear, or damage. Ensure the spool rotates freely and the line is properly wound.
3. Clear Work Area: Remove stones, nails, wire, and other debris that could be thrown or damage the line.
4. Operation: Keep bystanders and pets at least 50 feet away. Never operate the tool above waist height.
5. Bump-Feed Technique: Tap the head on the ground at operating speed to advance line. Do not force or slam excessively.

WARNING! A worn or damaged cutting head can break and cause serious injury. Replace damaged parts immediately. Always disconnect the spark plug before performing any maintenance.

Installation

Ensure the brushcutter is turned off and the spark plug is disconnected.

1. Remove Old Head: Use the appropriate wrench to hold the drive shaft and loosen the retaining nut (counter-clockwise). Remove the old head.
2. Clean Spindle: Clean any debris from the brushcutter's drive spindle.
3. Install Autocut 25-2: Place the new head onto the spindle, aligning any drive lugs or splines.
4. Secure Nut: Thread the retaining nut on by hand, then tighten firmly with the wrench while holding the drive shaft. Do not overtighten.
5. Check Rotation: Manually rotate the head to ensure it spins freely without obstruction.

CAUTION! Incorrect installation can cause the head to detach during operation. Ensure the head is securely fastened.

Specifications

• Model: Autocut 25-2
• Line Diameter: 0.095 inch (2.4 mm)
• Line Length: 25 ft (7.6 m) pre-wound
• Feed System: Semi-automatic bump-feed
• Compatible Line: Stihl Polycut 2.4mm
• Mounting Thread: M10 x 1.25 LH (Left-Hand) or other (check model)
• Weight (approx.): 0.55 lbs (250 g)
• Material: Polycarbonate housing, steel components
• Compatible Tools: Select Stihl FS, FC, or HLA models. Consult your dealer or the compatibility chart.

Operation

Starting and using the bump-feed system correctly ensures optimal cutting and line life.

1. Starting: Start the brushcutter on a clear, flat surface according to its manual.
2. Line Length: Before starting, pull out two lengths of line (approx. 6-8 inches total) to ensure proper cutting by the integrated blade.
3. Bumping to Advance: While the tool is running at full throttle, gently tap the head on bare ground or hard surface. The centrifugal force will release a short length of line, which is then cut to the correct length by the blade.
4. Cutting Technique: Use a sweeping motion from side to side, cutting with the tip of the line. Avoid pushing the head into dense material.
5. Avoiding Damage: Do not use the head as a edger against walls, fences, or rocks. Do not bump on concrete or asphalt excessively.

Tip: Advance line frequently in small amounts rather than waiting until it is completely worn down. This maintains cutting efficiency.

Line Replacement

Replace the spool when line is depleted or if the spool is damaged.

1. Stop Engine & Disconnect Spark Plug: Ensure complete safety.
2. Remove the Head: Press down on the two locking tabs on the sides of the housing and lift off the cover.
3. Remove Old Spool: Lift the empty spool out of the housing.
4. Install New Spool: Place the new, pre-wound spool into the housing. Ensure the line ends are fed through the eyelets in the housing.
5. Replace Cover: Align the cover and press down until the locking tabs click into place.
6. Pull Out Line: Pull the line ends firmly to release them from the spool's retaining slots, leaving about 6-8 inches extended.

WARNING! Use only genuine Stihl Polycut 2.4mm line. Incorrect line can cause poor feeding, overheating, and head failure.

Maintenance & Cleaning

Regular maintenance ensures long life and reliable operation.

• After Each Use: Clean grass and debris from the head housing and cooling vents.
• Weekly Inspection: Check for cracks in the housing, wear on the cutting blade, and smooth rotation of the spool.
• Lubrication: Lightly lubricate the spindle thread and the underside of the head (where it contacts the retaining washer) with a silicone spray to prevent corrosion and sticking.
• Spool Replacement: Replace the entire spool assembly when line is depleted. Do not attempt to re-wind your own line onto the spool.

CAUTION! Never use gasoline or strong solvents to clean the plastic housing. Use a damp cloth only.

Storage

Store the brushcutter with the Autocut head in a dry, clean, and secure place.

1. Clean the head thoroughly.
2. Store the tool in an upright position or hang it on a wall.
3. Protect from extreme temperatures and direct sunlight.
4. If storing for an extended period, remove the head and store it separately in a plastic bag.

Warranty Information

The Stihl Autocut 25-2 head is covered by a limited warranty from Stihl Inc. The warranty period and terms may vary by region. Proof of purchase from an authorized Stihl dealer is required for warranty service. This warranty does not cover damage due to misuse, lack of maintenance, improper installation, or use of non-genuine Stihl parts and accessories. For warranty details and service, contact your local authorized Stihl dealer or visit www.stihlusa.com.

Troubleshooting

For Service: Contact your local authorized Stihl dealer for repairs and genuine parts. Do not attempt to repair a damaged housing.