Husqvarna 372XP Chainsaw Service Manual

The Husqvarna 372XP is a professional-grade chainsaw designed for demanding forestry and arborist work. This service manual provides detailed instructions for maintenance, troubleshooting, and repair of the 372XP model, covering the engine, fuel system, ignition, chain drive, and safety features. Below are key sections for safety, specifications, maintenance procedures, troubleshooting, and parts information.

1. Features at a Glance 2. Safety Information 3. Specifications 4. Maintenance Schedule 5. Engine Service 6. Fuel System 7. Ignition System 8. Chain & Bar Maintenance 9. Troubleshooting 10. Parts Diagram 11. Warranty & Support

Features at a Glance

Key components: X-Torq engine technology, Air Injection air cleaning system, Smart Start ignition, Combined choke/stop control, Adjustable oil pump, Side-mounted chain tensioner.

Feature	Description
X-Torq Engine	Reduces fuel consumption and exhaust emissions
Air Injection	Centrifugal air cleaning system for longer filter life
Smart Start	Easy starting with reduced resistance in starter cord
Combined Choke/Stop Control	Simplified starting and stopping operation
Adjustable Oil Pump	Manual adjustment of chain oil flow rate
Side-Mounted Chain Tensioner	Easy access for chain adjustment
Vibration Dampening	Low vibration levels for operator comfort
Chain Brake	Inertia-activated safety feature
Fuel Tank Capacity	0.95 liters (1.0 US qt)
Oil Tank Capacity	0.55 liters (0.58 US qt)

Safety Information

Always wear appropriate personal protective equipment (PPE) including helmet, eye protection, hearing protection, gloves, and chainsaw chaps or pants.

Read and understand the operator's manual before use.
Inspect chainsaw before each use for damage or loose parts.
Ensure chain brake is functioning properly.
Use proper fuel mixture (50:1 gasoline to 2-stroke oil).
Never operate chainsaw with damaged or missing safety devices.

WARNING! Chainsaws are dangerous tools that can cause serious injury or death. Always follow safety procedures and maintain control of the saw at all times.

Specifications

Engine Type: 2-stroke, single cylinder, X-Torq
Displacement: 70.7 cc (4.31 cu.in.)
Power Output: 5.1 hp (3.8 kW)
Idle Speed: 2,700 rpm
Maximum Power Speed: 9,000 rpm
Fuel/Oil Ratio: 50:1 (2% oil)
Recommended Bar Length: 15-24 inches (38-61 cm)
Chain Pitch: 3/8" or .325"
Weight (without bar/chain): 6.3 kg (13.9 lbs)
Spark Plug: NGK BPMR7A (Champion RCJ7Y)

Maintenance Schedule

Access maintenance points via appropriate covers and panels. Always disconnect spark plug before servicing.

Daily: Clean air filter, check chain tension and sharpness, inspect chain brake function, check for loose fasteners.

Weekly: Clean cooling fins, check spark plug condition, clean fuel filter, inspect anti-vibration elements.

Monthly: Clean carburetor air intake, check fuel lines for cracks, inspect clutch and sprocket, clean chain oil holes.

Annually: Replace fuel filter, check cylinder compression, inspect piston through exhaust port, replace spark plug.

Engine Service

Cylinder and Piston: Remove muffler to inspect piston and cylinder walls for scoring. Compression should be 140-160 psi.

Remove spark plug and measure compression with gauge.
Inspect piston through exhaust port for scoring or damage.
Check cylinder walls for wear or damage.
Replace piston rings if compression is below 120 psi.
Clean carbon deposits from combustion chamber and exhaust port.

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

Fuel System

Supports standard 2-stroke fuel mixture. Carburetor: Walbro HDA or Zama C1M.

Fuel Tank: Check for cracks, clean sediment, replace fuel filter annually.
Fuel Lines: Inspect for cracks or hardening, replace if deteriorated.
Carburetor Adjustment: L screw (idle), H screw (high speed), T screw (idle speed).
Fuel Filter: Replace annually or if clogged.
Fuel Cap: Ensure vent is clear for proper fuel flow.

WARNING! Use fresh fuel (less than 30 days old) and proper 2-stroke oil mixture. Stale fuel can cause starting and performance issues.

Ignition System

Electronic ignition with Smart Start feature. Spark plug gap: 0.5 mm (0.020 in).

Remove spark plug and check electrode condition.
Adjust gap to 0.5 mm if necessary.
Test spark by grounding plug against cylinder and pulling starter.
Check ignition coil air gap: 0.3 mm (0.012 in).
Inspect spark plug wire for cracks or damage.

CAUTION! Never check for spark with spark plug removed from cylinder without properly grounding it. Fuel vapor could ignite.

Chain & Bar Maintenance

Proper chain tension: Should snap back when pulled from bar with light force.

Sharpening: Use proper round file size for chain pitch.
Depth Gauge: File to maintain proper height (0.025-0.030 in below cutter).
Bar Maintenance: Clean bar groove, flip bar regularly for even wear.
Sprocket: Inspect for wear, replace if teeth are hooked or worn.
Oil Flow: Adjust oil pump for proper lubrication.

WARNING! Always wear gloves when handling chain. A sharp chain is safer than a dull one as it requires less force.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, compression	Check fuel freshness, spark plug, compression; clean carburetor.
Engine runs poorly	Air filter, fuel filter, carb adjustment	Clean/replace air filter; replace fuel filter; adjust carburetor.
Chain won't oil	Oil tank, pump, holes	Check oil level; clean oil holes; adjust/replace oil pump.
Chain brake doesn't engage	Band, spring, mechanism	Inspect brake band for wear; check spring tension; clean mechanism.
Excessive vibration	AV mounts, balance	Check anti-vibration mounts; ensure bar/chain are properly balanced.

Reset: For electronic issues, disconnect spark plug wire for 30 seconds to reset ignition module.

Parts Diagram

Refer to official Husqvarna parts diagrams for exact part numbers and assembly order.

Cylinder and Piston Assembly: Includes cylinder, piston, rings, wrist pin, bearings.
Crankcase Assembly: Crankshaft, bearings, seals, connecting rod.
Carburetor Assembly: Complete carburetor with adjustment screws, diaphragm, gaskets.
Ignition System: Coil, flywheel, spark plug, wiring.
Chain Drive: Clutch, drum, sprocket, chain brake components.

Note: Always use Husqvarna part numbers when ordering replacement parts.

Warranty & Support

Husqvarna 372XP comes with commercial warranty (terms vary by region). For technical support, contact authorized Husqvarna dealers or visit www.husqvarna.com. Keep proof of purchase for warranty claims. Copyright © 2025 Husqvarna AB. All rights reserved.