STIHL TS 400 Service Manual

The STIHL TS 400 is a professional-grade cut-off saw designed for demanding construction, masonry, and rescue applications. This service manual provides comprehensive information for maintenance, troubleshooting, and repair procedures. It covers the engine, fuel system, ignition, cutting system, safety features, and specifications. Below are key sections for safety, features, maintenance, operation, and technical data.

Features at a Glance

Key components: 2-stroke engine, anti-vibration system, electronic ignition, quick-release cutting guard, ergonomic handles, and STIHL Ematic lubrication system.

Feature	Description
Engine Type	STIHL single-cylinder 2-stroke engine
Displacement	64.1 cm³ (3.91 cu. in.)
Power Output	3.0 kW (4.0 hp)
Fuel System	Diaphragm carburetor with manual choke
Ignition System	Electronic, capacitor discharge (CDI)
Starting System	STIHL Easy2Start™ or manual recoil
Anti-Vibration	Integrated damping elements in handles
Lubrication	STIHL Ematic system for reduced oil consumption
Cutting Wheel Size	300 mm (12 inches) maximum
Weight (without cutter)	Approx. 8.6 kg (19.0 lbs)

Safety Information

Read and understand all safety instructions before operation or service.

1. Personal Protective Equipment (PPE): Always wear safety glasses, hearing protection, gloves, steel-toed boots, and long pants.
2. Work Area: Keep bystanders and pets at a safe distance. Ensure secure footing.
3. Tool Inspection: Check for loose parts, damage, or leaks before each use. Ensure guard is properly attached.
4. Fuel Safety: Refuel in well-ventilated area with engine off and cool. Use STIHL MotoMix or proper fuel/oil mix.
5. Kickback Awareness: Be aware of potential kickback; always use two hands and proper stance.

WARNING! Failure to follow safety instructions can result in serious injury or death. Never operate a damaged or improperly maintained saw.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Interval	Task
Before each use	Check fuel level, oil level, guard attachment, and general condition.
Daily	Clean air filter, check spark plug, inspect cutting wheel for damage.
Weekly	Clean cooling fins, check anti-vibration elements, inspect fuel lines.
Monthly	Clean carburetor (if needed), check ignition system, inspect throttle linkage.
Every 6 months	Replace fuel filter, check clutch assembly, inspect drive shaft.
Annually	Professional inspection recommended. Replace worn parts per parts list.

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

Specifications

• Model: STIHL TS 400 Cut-Off Saw
• Engine: 2-stroke, air-cooled, single cylinder
• Displacement: 64.1 cm³
• Bore x Stroke: 48 mm x 35.4 mm
• Power Output: 3.0 kW at 9,500 rpm
• Idle Speed: 2,800 rpm
• Max. Engine Speed: 11,500 rpm
• Fuel/Oil Mix: 50:1 (STIHL HP Ultra or equivalent)
• Fuel Tank Capacity: 0.65 L (22 fl. oz.)
• Oil Tank Capacity: 0.26 L (8.8 fl. oz.)
• Sound Pressure Level: 106 dB(A) typical
• Vibration Level (handles): Left: 4.5 m/s², Right: 6.5 m/s²

Controls and Components

Familiarize yourself with all controls before operation.

Main Components: Throttle trigger with lockout, Stop switch, Choke lever, Primer bulb, Decompression valve (if equipped), Handle with anti-vibration, Quick-release guard mechanism, Cutting wheel spindle lock.

Operation: Engage lockout before pulling throttle. Use choke for cold starts. Always use both hands during cutting.

Maintenance Points: Air filter cover, Spark plug, Fuel cap, Oil cap, Carburetor adjustment screws (H, L, LA).

Fuel System Service

Proper fuel mix and system maintenance are critical.

1. Fuel Mix: Use 50:1 mix of unleaded gasoline (min. 89 octane) with STIHL HP Ultra 2-stroke oil.
2. Fuel Filter: Replace if clogged. Access through fuel tank opening.
3. Carburetor Adjustment: Factory set. Only adjust H and L screws if necessary using tachometer.
4. Fuel Lines: Inspect for cracks or leaks. Replace if damaged.
5. Fuel Tank Vent: Ensure vent is clear to prevent vacuum lock.

WARNING! Gasoline is highly flammable. No smoking during refueling or service.

Ignition System

Electronic ignition (CDI) requires minimal maintenance.

• Spark Plug: Type: BPMR 7A (NGK) or equivalent. Gap: 0.5 mm (0.020 in.). Replace if electrodes are worn or fouled.
• Ignition Module: Sealed unit. Test with ignition tester if no spark. Replace if faulty.
• Stop Switch: Test for continuity. Ensure wire is connected to spark plug.
• Flywheel: Check for damage or sheared key if timing is off.

Tip: Always disconnect spark plug wire before testing ignition components.

Cutting System & Guard

The cutting wheel and guard are critical for safe operation.

1. Cutting Wheel Installation: Use correct flange washers and nut. Tighten with spindle lock engaged.
2. Wheel Inspection: Check for cracks, uneven wear, or missing segments. Replace damaged wheels immediately.
3. Guard Adjustment: Quick-release allows easy positioning. Ensure guard covers top of wheel during operation.
4. Spindle Bearing: Check for play or roughness. Lubricate per schedule.
5. Clutch: Centrifugal clutch. Inspect shoes for wear. Replace if slipping or not engaging.

CAUTION! Never operate without the proper guard in place. Use only STIHL-approved cutting wheels.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, flooded, bad spark, clogged filter	Check fuel, dry plug, check spark, clean filter.
Engine runs poorly	Dirty air filter, carb adjustment, fuel line	Clean filter, adjust carb, inspect lines.
Loss of power	Clogged muffler, carbon buildup, worn piston	Clean muffler, decarbonize, inspect cylinder.
Excessive vibration	Unbalanced wheel, loose parts, bad AV mounts	Balance wheel, tighten fasteners, check mounts.
Oil leakage	Loose oil cap, damaged tank, faulty pump	Tighten cap, inspect tank, test oil pump.
Clutch slipping	Worn shoes, oily clutch, weak springs	Replace clutch assembly, clean drum.

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

Parts List & Diagrams

Refer to official STIHL parts diagrams for part numbers and assembly order. Common replacement parts include:

• Air filter element
• Spark plug
• Fuel filter
• Carburetor repair kit
• Clutch assembly
• Anti-vibration buffers
• Cutting wheel guard
• Starter rope

Note: Always use genuine STIHL parts to ensure performance and safety.

Warranty & Support

STIHL Limited Warranty: Refer to your warranty card for specific terms and duration.

Technical Support: Contact an authorized STIHL servicing dealer for repairs beyond basic maintenance.

Manual Updates: For the latest version, visit the STIHL website or contact customer service.

Contact: STIHL Incorporated, 536 Viking Drive, Virginia Beach, VA 23452. Customer Service: 1-800-467-8445. Website: www.stihlusa.com.