Husqvarna 55 Rancher Shop Manual

The Husqvarna 55 Rancher is a professional-grade chainsaw designed for demanding forestry and ranch work. This shop manual provides comprehensive technical information for maintenance, repair, and troubleshooting. It covers the 55 Rancher model with a 55cc engine, featuring automatic oiling, anti-vibration system, and a 15-18 inch bar. Below are key sections for safety, specifications, maintenance procedures, engine repair, fuel system, ignition, troubleshooting, and parts diagrams.

Features at a Glance

Key components: 55cc 2-stroke engine, Automatic chain oiler, Anti-vibration system, Quick-release air filter, Combined choke/stop control, Side-mounted chain tensioner.

Safety Precautions

Always wear proper PPE: helmet, eye protection, hearing protection, gloves, chainsaw chaps, and steel-toed boots.

1. Work area safety: Clear work area of obstacles and bystanders.
2. Chain brake: Test before each use; ensure it engages properly.
3. Fuel handling: Mix fuel outdoors; use Husqvarna 2-stroke oil at 50:1 ratio.
4. Kickback zone: Avoid contact with upper quadrant of bar tip.
5. Transport: Engage chain brake and install scabbard.

WARNING! Operating a chainsaw is dangerous. Read and understand all safety instructions before use. Never operate when fatigued or under influence.

Specifications

• Model: Husqvarna 55 Rancher.
• Engine Type: 2-stroke, single cylinder, air-cooled.
• Bore x Stroke: 45 mm x 34 mm.
• Cylinder displacement: 55 cc.
• Maximum power speed: 9000 rpm.
• Idle speed: 2700 rpm.
• Spark plug: Champion RCJ7Y or NGK BPMR7A, gap 0.020 inch (0.5 mm).
• Carburetor: Walbro HDA-159 or Zama C1Q-DM9.
• Fuel mixture: 50:1 (2% oil) with 89+ octane gasoline and Husqvarna 2-stroke oil.
• Chain brake engagement time: < 0.12 seconds.

Maintenance Schedule

Daily or before each use: Check chain tension, sharpness, and lubrication; inspect for loose fasteners; clean air filter; check chain brake function.

Weekly (or every 10 hours): Clean cooling fins; check spark plug condition; clean fuel filter; inspect anti-vibration elements.

Monthly (or every 50 hours): Replace spark plug; clean carburetor air intake; check fuel lines for cracks; clean cylinder exhaust port.

Yearly (or every 100 hours): Replace fuel filter; check clutch and sprocket wear; inspect ignition system; replace air filter if damaged.

Engine Repair

Cylinder and piston: Remove muffler to inspect piston through exhaust port. Scoring indicates air leak or lubrication failure.

1. Compression test: Should be 120-150 psi. Low compression indicates worn piston rings or cylinder.
2. Crankcase seals: Check for leaks with pressure/vacuum test (7 psi).
3. Cylinder removal: Remove engine cover, carburetor, ignition module, then cylinder bolts.
4. Piston installation: Arrow on piston crown must point toward exhaust port.

Torque specifications: Cylinder bolts: 10 Nm (7.4 ft-lb). Connecting rod bolts: 8 Nm (5.9 ft-lb).

Fuel System

Carburetor adjustment: H - High speed mixture (affects power at full throttle). L - Low speed mixture (affects idle and acceleration). T - Idle speed screw.

1. Initial settings: Turn H and L screws clockwise until lightly seated, then back out 1 turn each.
2. Final adjustment: Warm up engine. Adjust L for smooth acceleration. Adjust H for maximum RPM then rich slightly (100-200 RPM drop).
3. Fuel filter: Replace if clogged or annually.
4. Fuel lines: Check for cracks, hardening, or leaks. Replace if damaged.

Tip: Always use fresh fuel (less than 30 days old) to prevent carburetor issues.

Ignition System

Electronic ignition module: Non-adjustable. Check air gap: 0.010 inch (0.25 mm) between flywheel and coil legs.

1. Spark test: Remove spark plug, connect to ignition wire, ground against cylinder, pull starter. Look for strong blue spark.
2. No spark: Check stop switch wire for continuity to ground when off.
3. Ignition coil resistance: Primary: 0.5-1.5 ohms. Secondary: 8-15 kohms.
4. Flywheel key: Check for shearing if timing is off.

WARNING! Never run engine without spark plug properly grounded during testing.

Chain & Bar Maintenance

Chain sharpening: Use 5/32 inch (4.0 mm) round file with guide. Maintain 30° cutting angle, 10° top plate angle.

1. File each cutter equally to maintain balance.
2. Depth gauges: File to 0.025 inch (0.65 mm) below cutter edge.
3. Bar maintenance: Clean bar groove weekly; flip bar monthly for even wear.
4. Sprocket: Replace if worn or every 2-3 chains.
5. Chain tension: Adjust when chain sags from bar rails. Proper tension: chain should snap back when pulled from bar.

CAUTION! Always wear heavy gloves when handling chain. Ensure chain brake is engaged during maintenance.

Troubleshooting

Reset: For electronic issues, disconnect spark plug wire and pull starter 5 times to reset ignition module.

Parts Diagrams

Refer to Husqvarna parts catalog 505 87 02-01 for complete diagrams. Key assemblies:

1. Cylinder and piston assembly (Part #501 84 41-02)
2. Carburetor kit (Part #530 03 53-01)
3. Ignition module (Part #544 11 61-01)
4. Clutch assembly (Part #501 87 65-01)
5. Chain brake band (Part #501 84 47-01)
6. Anti-vibration mounts (Part #501 85 56-01)

Note: Always use genuine Husqvarna parts for optimal performance and safety.

Warranty & Support

Husqvarna 55 Rancher comes with a 2-year consumer warranty and 90-day commercial warranty from date of purchase. Warranty covers defects in materials and workmanship. Not covered: normal wear, misuse, improper maintenance, or non-Husqvarna parts.

For technical support, contact Husqvarna Forest & Garden Company: 1-800-487-5962 or visit www.husqvarna.com. Have model number (55 Rancher) and serial number (located on crankcase) ready.

Service Centers: Authorized Husqvarna dealers provide repair services and genuine parts.