Husqvarna 235 Chainsaw Service Manual

The Husqvarna 235 is a lightweight, professional-grade chainsaw designed for demanding cutting tasks. This service manual provides detailed instructions for maintenance, troubleshooting, and repair of the chainsaw's engine, cutting equipment, and safety systems. Below are key sections covering safety, specifications, maintenance procedures, troubleshooting, and parts information.

Features at a Glance

Key components: X-Torq® engine for reduced emissions, Smart Start® system for easy starting, LowVib® anti-vibration system, combined choke/stop control, inertia-activated chain brake, side-mounted chain tensioner.

Safety Information

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

1. Work area safety: Clear work area of obstacles and ensure secure footing.
2. Fuel safety: Refuel in well-ventilated area with engine stopped and cooled.
3. Chain brake: Test chain brake function before each use.
4. Kickback: Be aware of kickback zone; use reduced-kickback chain and bar.

WARNING! Never operate a chainsaw with damaged, improperly adjusted, or incorrectly assembled safety devices. Always follow local regulations.

Technical Specifications

• Engine Model: Husqvarna 235
• Cylinder Bore: 38 mm (1.5 in)
• Piston Stroke: 33 mm (1.3 in)
• Compression Ratio: 9.5:1
• Ignition System: Electronic, air gap 0.30 mm (0.012 in)
• Spark Plug: Champion RCJ7Y or equivalent, gap 0.5 mm (0.020 in)
• Carburetor: Zama C1Q, adjustable H, L, and T screws
• Idle Speed: 2700 ± 150 rpm
• Maximum Power Speed: 9000 rpm
• Fuel Mix: 50:1 (2% oil) with Husqvarna XP+ or equivalent quality 2-stroke oil

Maintenance Schedule

Access maintenance points via side covers and air filter cover.

Daily: Clean air filter, check chain tension and sharpness, inspect chain brake function, check all nuts and bolts for tightness.

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

Monthly: Clean carburetor air intake, check starter mechanism, inspect clutch and sprocket, clean exhaust port and spark arrestor screen.

Yearly: Replace fuel filter, check fuel lines, inspect cylinder and piston through exhaust port, check all safety devices.

Engine Service

Engine disassembly requires special tools including piston stop, flywheel puller, and torque wrench.

1. Cylinder and piston: Remove muffler to inspect piston and cylinder. Look for scoring or excessive wear.
2. Crankshaft seals: Check for leaks by pressure testing crankcase (0.5 bar/7 psi).
3. Connecting rod: Check side play (max 0.35 mm/0.014 in) and up/down play (none allowed).
4. Bearings: Check main bearings for smooth rotation without play or noise.

Torque Specifications: Cylinder nuts 10 Nm (7.4 ft.lb), Spark plug 25 Nm (18.4 ft.lb), Flywheel nut 40 Nm (29.5 ft.lb).

Cutting Equipment

Proper chain maintenance is critical for safety and performance.

1. Chain tension: Adjust with side tensioner when chain is cool. Proper tension allows chain to snap back when lifted from bar.
2. Chain sharpening: Use round file 4.0 mm (5/32") at 30° angle. Maintain consistent depth gauge height (0.65 mm/0.025 in).
3. Bar maintenance: Clean bar groove regularly. Flip bar monthly for even wear. Check for straightness and groove wear.
4. Sprocket: Check drive sprocket for wear. Replace if teeth are hooked or worn more than 0.5 mm (0.020 in).

Tip: Always use genuine Husqvarna chains, bars, and sprockets matched to your saw model.

Fuel System

Supports standard 2-stroke fuel mix. Carburetor adjustment requires tachometer.

1. Fuel filter: Replace annually or when clogged. Access through fuel tank opening.
2. Fuel lines: Check for cracks or hardening. Replace if damaged.
3. Carburetor adjustment: Initial settings: L=1 turn out, H=1 turn out. Fine-tune at operating temperature.
4. Fuel pump: Diaphragm pump integrated in carburetor. Check diaphragm for cracks or stiffness.

WARNING! Never run engine without air filter. Dirt ingestion causes rapid engine wear.

Ignition System

Electronic ignition with fixed timing. No points or condenser to adjust.

Spark plug: Check electrode gap (0.5 mm/0.020 in). Replace if electrodes are worn or insulator is cracked. Ignition coil: Check resistance - primary 0.2-0.3 Ω, secondary 8-10 kΩ. Stop switch: Check continuity (closed when pressed). Flywheel: Check magnets for damage or looseness. Air gap: 0.30 mm (0.012 in) between flywheel and coil legs.

Troubleshooting

Compression Test: Minimum 110 psi (7.6 bar) for proper operation.

Parts List & Diagrams

Refer to Husqvarna Genuine Parts Catalog for complete illustrated parts breakdown. Key part numbers:

• Cylinder Kit: 545 08 74-01
• Piston Kit: 545 08 75-01
• Carburetor Kit: 545 07 47-01
• Ignition Module: 545 08 77-01
• Clutch Assembly: 545 08 78-01
• Chain Brake Band: 545 08 79-01
• AV Mount Set: 545 08 80-01

CAUTION! Use only genuine Husqvarna parts to maintain performance, safety, and warranty coverage.

Warranty & Support

Husqvarna 235 carries a commercial warranty (details vary by region). Proof of purchase required. Warranty does not cover wear items (chains, bars, sprockets, filters, spark plugs) or damage from improper use, lack of maintenance, or non-genuine parts.

For technical support, contact authorized Husqvarna service dealers only. For dealer locator and additional resources, visit www.husqvarna.com or contact Husqvarna Customer Support at 1-800-487-5962.