Stihl FS 55 C Manual

The Stihl FS 55 C is a lightweight, professional-grade gasoline-powered string trimmer/brushcutter designed for demanding clearing and trimming tasks. It features a powerful 2-stroke engine with STIHL anti-vibration system, a loop handle for comfortable operation, a straight shaft with a gearbox, a Tap'N Go™ cutting head for easy line advance, and a PolyCut™ head for brush cutting. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Safety Instructions 3. Assembly & Preparation 4. Specifications 5. Controls and Components 6. Fuel & Lubrication 7. Starting & Operation 8. Cutting Attachments 9. Maintenance & Storage 10. Warranty Information 11. Troubleshooting

Features at a Glance

Key components: 2-stroke engine, Loop handle, Straight drive shaft with gearbox, Tap'N Go™ cutting head, PolyCut™ head, Throttle trigger lockout, Stop switch.

FeatureDescription
EngineSTIHL 2-stroke, air-cooled, single-cylinder
Anti-Vibration SystemReduces operator fatigue
Drive ShaftStraight, solid design with gearbox
Cutting HeadTap'N Go™ for easy line advance; PolyCut™ head for brush
HandleLoop handle for balanced, two-handed control
Throttle TriggerWith lockout for safety
Stop SwitchImmediately stops engine
Fuel TankIntegrated, see-through for fuel level check
Spark PlugEasily accessible for maintenance
Air FilterEasy-to-clean foam element

Safety Instructions

Read and understand all instructions before use. Wear appropriate PPE.

  1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, sturdy gloves, long pants, and closed-toe shoes.
  2. Work Area Safety: Clear area of bystanders, especially children and pets. Be aware of hidden objects like wires or stones.
  3. Fuel Safety: Refuel outdoors only, with engine off and cool. Use approved fuel container. Wipe up spills immediately.
  4. Operation Safety: Hold unit firmly with both hands. Keep cutting attachment below waist level. Do not operate on unstable surfaces.

WARNING! Risk of serious injury or death from rotating cutting attachment, kickback, flying debris, and fuel fire/explosion. Never operate without proper guards and PPE.

Assembly & Preparation

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

  1. Attach Handle/Shaft: Align handle with shaft and secure with provided bolts. Ensure throttle cable moves freely.
  2. Install Cutting Attachment: Select Tap'N Go™ head or PolyCut™ head. Follow specific instructions for each. Ensure guard is properly installed.
  3. Add Fuel/Oil Mix: Use only high-quality 2-stroke engine oil mixed with unleaded gasoline (50:1 ratio for STIHL MotoMix® or oil). Fill fuel tank.
  4. Check Controls: Verify throttle trigger lockout and stop switch function correctly before starting.

CAUTION! Ensure all fasteners are tight. Do not force parts during assembly.

Specifications

Controls and Components

Main Controls: Throttle trigger with lockout, Stop switch, Choke lever, Primer bulb, Fuel tank cap, Decompression valve (if equipped).

Handle Area: Throttle trigger lockout must be depressed before throttle can be engaged. Stop switch moves to STOP position to kill engine.

Engine Area: Choke lever for cold starts. Primer bulb to draw fuel into carburetor. Decompression valve reduces pulling resistance for starting.

Cutting Attachment: Guard MUST always be in place. Tap'N Go™ head: Tap on ground while at high idle to advance line. PolyCut™ head: For cutting brush and tough weeds.

Fuel & Lubrication

Use only fresh, unleaded gasoline with a minimum octane rating of 89 (RON). Mix with a high-quality 2-stroke engine oil at 50:1 ratio. STIHL MotoMix® pre-mixed fuel is recommended.

  1. Clean area around fuel cap.
  2. Unscrew cap slowly to release pressure.
  3. Fill with correct fuel/oil mixture. Do not overfill.
  4. Tighten cap securely and wipe away any spills.

Gearbox Lubrication: Lubricate gearbox with STIHL gear oil periodically as specified in maintenance schedule.

WARNING! Gasoline is extremely flammable. No smoking. Engine must be off and cool.

Starting & Operation

Starting Procedure (Cold Engine):

  1. Place unit on firm, flat ground. Ensure cutting attachment is clear.
  2. Press fuel primer bulb 5-10 times until fuel is visible.
  3. Move choke lever to closed position (if equipped).
  4. Set stop switch to RUN position.
  5. Depress throttle trigger lockout and squeeze throttle trigger. While holding, pull starter rope briskly until engine fires.
  6. Move choke lever to open position immediately.
  7. Pull starter rope again to start engine. Allow to warm up at idle.

Operation: Hold unit with both hands. Use a slow, sweeping motion from right to left. Let the tool do the work; do not force it.

Cutting Attachments

Tap'N Go™ Cutting Head (Standard): For trimming grass and light weeds. To advance line: Run engine at high idle (not full throttle) and tap head firmly on bare ground.

PolyCut™ Head (Optional): For cutting dense weeds, brush, and saplings up to approx. 10 mm thick. Install according to specific instructions.

Changing Line: For Tap'N Go head, use only STIHL recommended nylon line of correct diameter. Wind line onto spool following directional arrows.

WARNING! Always stop engine and ensure it is cool before handling or changing any cutting attachment.

Maintenance & Storage

Daily/Before Use: Check for loose fasteners, damaged parts, and fuel leaks. Clean air filter if dirty. Inspect cutting attachment and guard.

Regular Maintenance: Clean spark arrestor screen (if equipped). Check spark plug condition and gap. Clean cooling fins. Lubricate gearbox as needed.

End of Season/Storage: 1. Run engine until fuel tank is empty. 2. Remove spark plug and add a teaspoon of 2-stroke oil into cylinder. Pull starter rope slowly to distribute oil, then reinstall plug. 3. Thoroughly clean entire unit. 4. Store in a dry, secure place, out of reach of children.

CAUTION! All maintenance should be performed with engine off and cool. Use only STIHL replacement parts.

Warranty Information

This STIHL product is covered by a limited warranty. Proof of purchase from an authorized STIHL dealer is required. Warranty covers defects in material and workmanship under normal use and maintenance. It does not cover damage from misuse, neglect, improper fuel, or unauthorized repairs. For full warranty terms, see the warranty card included with your unit or contact your STIHL dealer.

Troubleshooting

SymptomPossible CauseCorrective Action
Engine will not startNo fuel, flooded, spark plug faulty, switch offCheck fuel; wait if flooded; check/chang spark plug; ensure switch is ON.
Engine starts then diesDirty air filter, clogged fuel filter, carburetor adjustmentClean/replace air filter; replace fuel filter; see dealer for carb adjustment.
Loss of powerDirty air filter, clogged spark arrestor, old fuelClean air filter & spark arrestor screen; use fresh fuel mix.
Excessive vibrationLoose parts, bent drive shaft, unbalanced cutting attachmentTighten all fasteners; inspect shaft/attachment for damage.
Line not advancingLine too short, head dirty/worn, incorrect techniqueReload line; clean or replace head; tap firmly on bare ground at high idle.
Cutting attachment does not spinDrive shaft disconnected, gearbox damagedCheck shaft connection; inspect gearbox for damage (see dealer).

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

Support: Visit www.stihlusa.com or contact your local STIHL dealer.

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