STIHL Leaf Blower Repair Manual

The STIHL Leaf Blower Repair Manual provides comprehensive guidance for troubleshooting, maintaining, and repairing STIHL handheld and backpack leaf blowers. This manual covers safety precautions, common issues, step-by-step repair procedures, parts identification, and maintenance schedules for models including BR 200, BR 350, BR 400, BR 500, and similar series. Below are key sections for safety, troubleshooting, disassembly, repair, reassembly, and parts ordering.

Safety Precautions

Before performing any repairs, ensure the leaf blower is turned off, cooled down, and the spark plug wire is disconnected to prevent accidental starting.

Tools & Equipment Required

Basic and specialized tools needed for STIHL leaf blower repair.

1. STIHL combination wrench set or metric socket set (8mm-13mm).
2. Screwdrivers (flathead and Phillips #2).
3. Needle-nose pliers and regular pliers.
4. Spark plug wrench and gap tool.
5. Carburetor adjustment tool (splined or flat).
6. Compression tester (optional for engine diagnosis).
7. Fuel line clamp and fuel line pick set.
8. Torque wrench (in-lb and ft-lb ranges).
9. Clean rags and shop towels.
10. Parts cleaning tray and solvent.

WARNING! Using incorrect tools can damage components and void warranty. Always refer to the specific model's manual for tool requirements.

Common Symptoms & Diagnosis

Identify the problem before disassembly to save time and effort.

1. Engine won't start: Check fuel, spark plug, air filter, and carburetor.
2. Engine starts then dies: Likely fuel delivery issue (clogged filter, bad fuel line, carburetor adjustment).
3. Loss of power: Check air filter, spark arrestor, fuel filter, and compression.
4. Excessive vibration: Inspect fan, impeller, and engine mounts for damage or imbalance.
5. Unusual noise from fan housing: Debris in impeller or worn bearings.
6. Throttle not responding: Check throttle cable, linkage, and carburetor spring.
7. Fuel leak: Inspect fuel lines, tank, carburetor gaskets, and primer bulb.

CAUTION! Always diagnose systematically. Do not force components; disassemble carefully noting part orientation.

Engine Troubleshooting

• Compression Test: Should read 90-120 psi (varies by model). Low compression indicates worn piston rings, cylinder, or head gasket.
• Spark Test: Remove spark plug, reconnect wire, ground electrode to cylinder, pull starter. Look for strong blue spark.
• Fuel Delivery: Ensure fuel flows from tank to carburetor. Check for clogged filter, pinched line, or faulty primer bulb.
• Air Supply: Inspect air filter for dirt; clean or replace. Check for obstructions in intake.
• Exhaust: Remove spark arrestor screen; clean carbon deposits with wire brush.
• Ignition Module: If no spark, test ignition coil with multimeter per STIHL specs; replace if out of range.
• Rewind Starter: If rope doesn't retract or engine doesn't turn, inspect spring, pulley, and pawls.

Fuel System Repair

Step-by-step fuel system service for common STIHL leaf blower models.

Fuel Line Replacement:

1. Drain fuel tank completely.
2. Remove air filter cover and filter to access carburetor.
3. Disconnect fuel lines from carburetor and tank (note routing).
4. Use pick to remove old lines from tank grommets.
5. Install new lines, ensuring they reach bottom of tank (fuel pickup) and vent line is shorter.
6. Reconnect to carburetor (typically larger diameter line to fuel inlet, smaller to purge/return).
7. Test for leaks before final assembly.

Fuel Filter Replacement: Attach new filter to pickup line before inserting into tank.

Tip: Use STIHL OEM fuel lines for proper fit and ethanol resistance.

Ignition System Repair

Testing and replacing ignition components.

1. Disconnect spark plug wire and remove plug.
2. Check plug gap (typically 0.020 inches); adjust or replace if electrode is worn.
3. For no spark: Check stop switch wire for continuity; disconnect to test if switch is faulty.
4. Test ignition coil air gap (should be 0.008-0.012 inches) between coil legs and flywheel magnets.
5. Use multimeter to test primary and secondary coil resistance (refer to model-specific values).
6. Replace coil if out of specification or visibly damaged.
7. Reassemble, ensuring flywheel key is not sheared and coil gap is set correctly.

WARNING! Never test for spark near fuel or flammable vapors. Keep plug grounded to cylinder during test.

Carburetor Adjustment & Repair

STIHL carburetors (e.g., Zama, Walbro) have H (high), L (low), and LA (idle) adjustment screws.

1. Initial settings: Turn H and L screws gently clockwise to seat, then back out 1 turn each (typical).
2. Start engine and warm up for 3-5 minutes.
3. Adjust idle speed (LA) so engine runs smoothly without engaging clutch.
4. Adjust L screw for smoothest acceleration from idle.
5. Adjust H screw for maximum RPM, then rich slightly (counterclockwise 1/8 turn) to protect engine.
6. Re-check idle after H/L adjustments.
7. If cleaning is needed, disassemble carburetor, soak in cleaner, replace diaphragm and gasket kit, and reassemble.

CAUTION! Do not over-tighten adjustment screws. Use correct tool to avoid stripping.

Fan & Impeller Repair

Addressing airflow and vibration issues.

Tip: Balance impeller by checking for wobble; replace if unbalanced to prevent vibration.

Throttle & Control Cable Repair

Ensuring proper throttle response and trigger operation.

Throttle cable replacement:

1. Remove air filter cover and filter.
2. Detach cable end from carburetor throttle lever.
3. Route new cable through handle and housing following original path.
4. Connect to throttle trigger assembly, adjusting for minimal free play.
5. Reconnect to carburetor, ensuring spring returns lever to idle position.
6. Test trigger for smooth operation before final assembly.

WARNING! Do not kink cable during installation. Lubricate cable lightly with cable lube if recommended.

Maintenance Schedule

Regular maintenance prevents major repairs and extends blower life.

• Daily/Before Use: Check for loose fasteners, leaks, and visible damage.
• Every 10 hours: Clean air filter; check spark plug condition.
• Every 20 hours: Replace fuel filter; clean spark arrestor screen.
• Every 50 hours: Replace spark plug; inspect fuel lines and carburetor diaphragm.
• Every 100 hours: Check compression; replace air filter element; inspect impeller and bearings.
• Seasonal: Drain fuel or add stabilizer for storage; run carburetor dry.
• As Needed: Replace worn throttle cable, starter rope, and vibration dampeners.

Parts Reference & Ordering

Use STIHL part numbers for ordering genuine replacement parts.

Ordering: Contact authorized STIHL dealer with model and serial number. Verify part numbers in the specific IPL (Illustrated Parts List).

Support: STIHL USA: 1-800-467-8445; www.stihlusa.com