Mac 335 Chainsaw Service Manual

The Mac 335 is a professional-grade chainsaw designed for demanding forestry and arborist work. This service manual provides comprehensive instructions for maintenance, troubleshooting, and repair of the 335 model, covering its 2-stroke engine, fuel system, cutting assembly, safety features, and electrical components. Below are key sections for safety, specifications, maintenance procedures, troubleshooting, and parts identification.

1. Safety Information 2. Specifications 3. Maintenance Schedule 4. Engine System 5. Fuel System 6. Cutting Assembly 7. Electrical System 8. Troubleshooting 9. Parts List & Diagrams 10. Warranty & Support

Safety Information

Critical safety warnings and precautions for operating and servicing the Mac 335 chainsaw.

Hazard	Precaution
Kickback	Always use proper grip, maintain chain sharpness, and avoid contact with bar tip.
Fuel Handling	Use approved fuel containers; refuel in well-ventilated area away from ignition sources.
Hot Surfaces	Allow engine to cool before performing maintenance on muffler or cylinder.
Chain Tension	Check and adjust tension before each use; chain should snap back when pulled.
Personal Protective Equipment (PPE)	Always wear safety glasses, hearing protection, gloves, chainsaw chaps, and steel-toe boots.

Specifications

Engine Type: 2-stroke, air-cooled, single cylinder.
Displacement: 54.3 cc.
Power Output: 3.5 kW (4.7 HP) @ 9,500 RPM.
Fuel Capacity: 0.55 L.
Oil Capacity (Chain): 0.26 L.
Bar Length Options: 16", 18", 20".
Chain Pitch: 3/8".
Weight (Powerhead): 5.9 kg.
Ignition System: Electronic (CDI).
Recommended Fuel Mix: 50:1 (Unleaded gasoline to 2-stroke oil).

Maintenance Schedule

Regular maintenance intervals to ensure optimal performance and longevity.

Before Each Use: Check chain tension, sharpness, and lubrication; inspect for loose fasteners.
Every 10 Hours: Clean air filter; check spark plug condition.
Every 20 Hours: Clean spark arrestor screen; inspect fuel filter.
Every 50 Hours: Replace air filter; clean cooling fins; inspect clutch and sprocket.
Every 100 Hours: Decarbonize exhaust port and muffler; check cylinder compression.
Annually: Replace fuel lines and filter; inspect anti-vibration mounts.

WARNING! Always disconnect spark plug wire before performing any maintenance.

Engine System

Procedures for servicing the engine cylinder, piston, carburetor, and ignition.

Carburetor Adjustment: Use H (High), L (Low), and T (Idle) screws. Initial settings: H - 1 turn out, L - 1 turn out, T - 1.5 turns out. Fine-tune for optimal performance.

Spark Plug: NGK BPMR7A, gap 0.5 mm. Replace if electrodes are worn or fouled.

Compression Test: Normal range: 120-150 PSI. Below 100 PSI indicates worn piston rings or cylinder.

Fuel System

Components include fuel tank, lines, filter, and carburetor.

Drain fuel before storage exceeding 30 days.
Replace fuel filter annually or if clogged.
Inspect fuel lines for cracks or leaks; replace if necessary.
Clean carburetor diaphragm and jets if engine runs poorly.

Tip: Use fresh, ethanol-free fuel to prevent carburetor varnish and corrosion.

Cutting Assembly

Maintenance of guide bar, chain, sprocket, and clutch.

Chain Sharpening: Use round file matching chain pitch (5.5 mm). Maintain 30° cutting angle, 10° top plate angle.
Bar Maintenance: Clean bar groove weekly; flip bar monthly for even wear.
Sprocket Inspection: Replace drive sprocket if teeth are hooked or worn.
Clutch Service: Inspect clutch shoes for wear; clean centrifugal clutch drum.
Chain Brake Test: Engage brake manually; ensure it stops chain within 0.15 seconds.

WARNING! Always wear cut-resistant gloves when handling chain.

Electrical System

CDI ignition, stop switch, and wiring harness.

Ignition Coil Test: Primary resistance: 0.5-1.5 Ω; Secondary: 8-15 kΩ.

Stop Switch: Ensure switch breaks continuity when engaged.

Wiring: Inspect for frayed or damaged wires, especially near vibration points.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine will not start	No spark, flooded, fuel issue	Check spark plug, ignition coil; dry plug; verify fuel flow and carburetor settings.
Engine starts then dies	Clogged fuel filter, air leak	Replace fuel filter; inspect intake manifold and crank seals.
Loss of power	Dirty air filter, clogged muffler	Clean/replace air filter; clean spark arrestor screen.
Chain does not turn	Clutch worn, sprocket damaged	Inspect clutch shoes and springs; replace drive sprocket.
Excessive vibration	Loose components, unbalanced chain	Tighten all fasteners; sharpen chain evenly; check anti-vibration mounts.
Chain oil not flowing	Clogged oil port, pump failure	Clean oil passages; inspect oil pump drive and diaphragm.

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

Parts List & Diagrams

Exploded views and part numbers for major assemblies (Engine, Fuel System, Cutting Attachment). Contact authorized Mac dealer for genuine replacement parts. Reference part number prefix: MAC-335-XXX.

Warranty & Support

Mac 335 chainsaw includes a 2-year commercial warranty against defects in materials and workmanship. Warranty is void if used with improper fuel mix, modified, or serviced by unauthorized personnel. For technical support and dealer locator, visit www.macchainsaws.com/support or call 1-800-555-MAC-1 (6221).