STIHL BR 600 Repair Service Manual

The STIHL BR 600 is a professional-grade backpack blower designed for demanding commercial and residential applications. This repair service manual provides comprehensive instructions for troubleshooting, maintenance, disassembly, repair, and reassembly of the BR 600 blower. It covers the engine (2-MIX technology), fuel system, ignition system, air filtration, cooling system, starter, clutch, fan impeller, harness tube, and controls. Intended for qualified technicians, it includes specifications, torque values, special tools, and detailed exploded-view diagrams.

Safety Precautions & General Information

Before any service, read all warnings. Use proper personal protective equipment (PPE).

Precaution	Description
Fuel Safety	Work in well-ventilated area; no sparks or flames. Use approved fuel containers.
Hot Surfaces	Allow engine to cool completely before disassembly to avoid burns.
Sharp Edges	Wear cut-resistant gloves when handling fan impeller, throttle linkage, etc.
Springs & Clips	Use eye protection; components under tension can fly off during disassembly.
Battery Disconnect	For electric start models, disconnect battery before servicing ignition or wiring.
Clean Work Area	Keep area free of debris to prevent contamination of fuel or engine systems.
Proper Tools	Use STIHL special tools where specified to avoid damage and ensure correct assembly.
Parts Replacement	Use only genuine STIHL replacement parts to maintain performance and safety.
Test Run	After repair, conduct a test run in a clear, open area, checking for leaks and abnormal operation.
Manual Reference	Always consult this manual for specific procedures and torque values.

Specifications & Technical Data

Key technical data for the STIHL BR 600 backpack blower.

• Engine Type: STIHL 2-MIX, single-cylinder, two-stroke.
• Displacement: 64.1 cm³ (3.91 cu. in.).
• Power Output: 3.6 bhp (2.7 kW).
• Idle Speed: 2,800 rpm.
• Maximum Power Speed: 7,500 rpm.
• Fuel/Oil Mix: 50:1 with STIHL HP Ultra or equivalent ISO-L-EGD certified oil.
• Fuel Tank Capacity: 1.6 L (54 fl. oz.).
• Air Filtration: Multi-stage air filter with pre-separation.
• Ignition System: Electronic, capacitor discharge (CDI).
• Starter: Rewind starter with decompression valve.
• Blower Tube Diameter: 57 mm.
• Maximum Air Velocity: 347 km/h (216 mph).
• Maximum Air Volume: 1,240 m³/h (730 cfm).
• Sound Pressure Level: 107 dB(A) (operator position).
• Vibration Levels: Left/Right Hand: 4.5/5.5 m/s².
• Weight (Dry): 10.6 kg (23.4 lbs).

Troubleshooting & Diagnostic Procedures

Systematic approach to identify and correct common operational faults.

Symptom	Possible Cause	Diagnostic & Corrective Action
Engine fails to start	1. No spark. 2. No fuel. 3. Flooded engine. 4. Faulty decompression valve.	1. Check spark plug, wire, and ignition module. 2. Verify fuel in tank, check fuel line and filter, carburetor diaphragm. 3. Remove plug, dry, crank with throttle open. 4. Test decompression valve seal and spring.
Engine starts but dies	1. Clogged fuel filter/vent. 2. Dirty air filter. 3. Faulty ignition under load. 4. Carburetor adjustment.	1. Replace fuel filter, clear tank vent. 2. Clean or replace air filter. 3. Check coil air gap and resistance. 4. Adjust H and L screws per manual.
Loss of power	1. Clogged spark arrestor. 2. Worn piston/cylinder. 3. Air leak (crank seals, gaskets). 4. Restricted muffler.	1. Clean spark arrestor screen. 2. Perform compression test; inspect for scoring. 3. Pressure test crankcase. 4. Check for carbon buildup in exhaust port and muffler.
Excessive vibration	1. Damaged or unbalanced fan impeller. 2. Loose engine mounts. 3. Bent crankshaft. 4. Worn clutch/damper.	1. Inspect impeller for cracks, clean debris. 2. Tighten all mounting bolts to spec. 3. Check runout with dial indicator. 4. Inspect clutch shoes and damper springs.
Abnormal noise	1. Foreign object in impeller housing. 2. Worn main bearings. 3. Connecting rod play. 4. Loose heat shield.	1. Remove housing cover and inspect. 2. Check for lateral play on crankshaft. 3. Disassemble and measure rod small/large end play. 4. Tighten or replace heat shield.

Maintenance Schedule & Procedures

Regular maintenance ensures longevity and optimal performance.

1. Daily/Before Use: Check for loose fasteners, leaks, and visible damage. Clean exterior.
2. After Each Use: Clean air filter pre-cleaner. Wipe down harness and controls.
3. Every 10 Operating Hours: Clean main air filter element (more often in dusty conditions).
4. Every 20 Operating Hours: Check spark plug condition and gap (0.5 mm / 0.020 in).
5. Every 50 Operating Hours: Replace fuel filter. Clean spark arrestor screen. Check impeller for damage and balance.
6. Every 100 Operating Hours: Replace air filter element. Check all fuel lines for cracks. Clean cooling fins.
7. Annually or Every 200 Hours: Replace spark plug. Clean carburetor and check diaphragms. Check clutch spring tension and shoe wear. Inspect harness and tube for cracks.
8. As Needed: Sharpen or replace fan impeller blades. Grease throttle and choke linkages.

WARNING! Always disconnect the spark plug boot before performing any maintenance.

Fuel System Repair

Components: Fuel tank, cap/vent, lines, filter, carburetor (Zama C1Q-S series).

1. Fuel Tank & Cap: Inspect for cracks. Clean tank. Ensure vent in cap is clear.
2. Fuel Lines: Replace if hardened, cracked, or discolored. Route correctly to avoid kinks.
3. Fuel Filter: Replace inline filter. Ensure it sits at bottom of tank.
4. Carburetor Service:
   • Remove carburetor from intake block.
   • Disassemble: Remove diaphragms (pump and metering), gaskets, needle valve, jets.
   • Clean all parts in ultrasonic cleaner or carburetor cleaner. Use compressed air to blow out all passages.
   • Inspect diaphragms for stiffness or tears; replace if defective.
   • Reassemble with new gasket/diaphragm kit. Set metering lever height to specification.
   • Initial Adjustments: H and L screws - turn in gently to seat, then back out 1 turn each as starting point.
5. Pressure/Vacuum Test: After reassembly, test carburetor and fuel lines for leaks using pressure pump.

Ignition System Repair

Components: Flywheel, ignition module (coil), spark plug, stop switch, wiring.

1. Spark Test: Remove plug, connect to boot, ground against cylinder, pull starter. Look for strong blue spark.
2. Spark Plug: Check electrode wear, gap (0.5 mm). Replace with recommended type (BOSCH WSR6F or equivalent).
3. Ignition Module:
   • Check air gap between coil legs and flywheel magnets (0.2-0.4 mm). Use feeler gauge.
   • Test primary and secondary resistance with multimeter (refer to values in spec sheet).
   • If faulty, replace module. Ensure wiring harness connections are clean and tight.
4. Flywheel: Check for broken magnets or cracks. Use puller (STIHL 1128 893 4500) for removal. Torque nut to 40 Nm (30 ft-lb) on reassembly.
5. Stop Switch Circuit: Test for continuity. Wire should be open circuit when switch is off, closed when on.

Engine Disassembly & Reassembly

Major engine service procedure.

1. Preparation: Clean exterior thoroughly. Remove blower tube, harness, fuel tank, and carburetor.
2. Cylinder & Piston:
   • Remove muffler and cylinder cover.
   • Remove cylinder base nuts, carefully lift cylinder.
   • Inspect cylinder bore for scoring. Measure wear. Hone if within service limits.
   • Remove piston pin circlips. Heat piston and push out pin. Inspect piston for cracks, ring grooves.
   • Check ring end gap in cylinder. Replace piston and rings if out of spec.
3. Crankshaft & Bearings:
   • Support crankcase halves. Separate using case splitter tool.
   • Inspect crankshaft for straightness (runout). Check main bearings for smooth rotation and no play.
   • Replace crank seals during reassembly. Lubricate seals lightly with 2-stroke oil.
4. Reassembly:
   • Use new gaskets and seals throughout.
   • Assemble piston to connecting rod, install new circlips (open end oriented correctly).
   • Lubricate cylinder, piston, and rings with oil. Compress rings and slide cylinder over piston.
   • Apply sealant to crankcase mating surfaces as specified. Assemble halves and torque case screws in crisscross pattern.
   • Torque cylinder base nuts to 20 Nm (15 ft-lb).

CAUTION! Label all parts and fasteners. Take photos during disassembly for reference.

Airflow System & Impeller Service

Components: Impeller housing, fan impeller, clutch assembly, driveshaft.

1. Impeller Removal: Remove housing cover. Lock crankshaft (use piston stop). Remove impeller nut (left-hand thread). Slide off impeller.
2. Impeller Inspection: Check for cracks, chips, or excessive wear on blades. Clean all debris. Balance if necessary.
3. Clutch Assembly: Inspect clutch shoes for wear and contamination. Check springs for fatigue. Replace as a set if worn.
4. Driveshaft & Bearings: Check shaft for straightness. Inspect support bearings in housing for smooth rotation; replace if gritty or loose.
5. Reassembly: Install impeller with key aligned. Torque nut to 50 Nm (37 ft-lb). Ensure housing seal is in place. Check impeller clearance to housing; adjust shims if needed.

Harness, Tube, & Control Repair

Ensuring operator comfort and control functionality.

1. Harness Inspection: Check for frayed straps, broken buckles, or torn padding. Replace entire harness if damaged.
2. Blower Tube: Inspect for cracks, especially near mounting flange. Ensure locking mechanism engages securely.
3. Throttle Trigger & Cable: Check for smooth operation. Lubricate cable with light oil if stiff. Adjust cable free play per manual.
4. Master Control Lever (STOP/CHOKE/THROTTLE LOCK): Disassemble handle. Clean and lubricate pivot points. Ensure return springs are functional.
5. Wiring Harness: For electric start models, check battery connections, starter solenoid, and switch for corrosion or damage.

Special Tools & Torque Specifications

Essential tools and critical fastener torque values.

Fastener / Component	Torque Specification	Notes / Special Tool
Cylinder Base Nuts	20 Nm (15 ft-lb)	M8 thread
Muffler Mounting Nuts