The STIHL TS 400 is a professional-grade cut-off saw designed for demanding construction, masonry, and rescue applications. This service manual provides comprehensive technical information for maintenance, troubleshooting, and repair. It covers the TS 400's 2-stroke engine, fuel system, ignition, cutting system, safety features, and all critical service procedures. Below are key sections for safety, specifications, maintenance schedules, component breakdown, troubleshooting, and parts lists.
Critical safety information for operating and servicing the STIHL TS 400 cut-off saw. Failure to follow these instructions can result in serious injury or death.
| Hazard | Precaution |
|---|---|
| Kickback | Always use the correct guard. Hold saw firmly with both hands. Do not cut above shoulder height. |
| Rotating Cutting Wheel | Ensure guard is properly installed. Never operate without guard. Allow wheel to stop before setting saw down. |
| Fuel & Fire | Refuel in well-ventilated area, engine off and cool. Use only STIHL-approved gasoline/oil mix. No smoking. |
| Hot Surfaces | Allow engine and muffler to cool before performing service or touching. |
| Vibration | Wear anti-vibration gloves during extended use. Take regular breaks. |
| Noise | Wear approved hearing protection during operation. |
| Dust & Debris | Always wear safety glasses, face shield, and dust mask appropriate for material being cut. |
Regular maintenance is essential for safe operation, performance, and longevity.
WARNING! Always disconnect the spark plug boot before performing any maintenance.
Detailed service procedures for the 2-stroke engine components.
Cylinder & Piston: Inspection for scoring, wear, and ring gap. Piston ring installation orientation. Cylinder base gasket replacement.
Crankcase & Crankshaft: Sealing check, main bearing inspection, and crankshaft runout measurement.
Fuel System: Fuel tank, cap, and line inspection. Fuel filter replacement procedure. Fuel pump (if equipped) diaphragm check.
Air Filtration: Service of pre-filter and main foam/felt filter element. Never operate with a dirty or damaged air filter.
Components related to the cutting attachment and operator safety.
CAUTION! A cracked or damaged cutting wheel can explode. Never use a wheel that has been dropped or impacted.
Electronic Capacitor Discharge Ignition (CDI) system service.
| Component | Test/Procedure |
|---|---|
| Spark Plug | Check electrode wear, ceramic insulator for cracks. Set gap to 0.5 mm (0.020 in). |
| Ignition Module (CDI) | Resistance check per manual specifications. Check for physical damage or corrosion. |
| Stop Switch & Wiring | Continuity test. Ensure switch grounds the ignition when activated. |
| Flywheel & Magneto | Check for cracks, clean magnets. Check key and keyway for shearing. Torque nut to specification. |
Note: The ignition timing is fixed and non-adjustable on this model.
Procedure for adjusting the WT series carburetor. Requires a tachometer.
WARNING! An overly lean H setting will cause engine overheating and severe damage.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine will not start | No spark, flooded, fuel issue, compression | Check spark, plug condition. Dry plug if flooded. Check fuel line/filter/carb. Test compression. |
| Engine starts then dies | Clogged fuel filter, tank vent, carb adjustment | Replace fuel filter. Clean tank vent. Check carburetor settings and diaphragms. |
| Loss of power | Dirty air filter, clogged spark arrestor, carb adjustment, exhaust port carbon | Clean/replace air filter. Clean spark arrestor. Adjust carb. Decarbonize exhaust. |
| Excessive vibration | Unbalanced/damaged cutting wheel, loose fasteners, worn anti-vibration mounts | Replace cutting wheel. Tighten all fasteners. Inspect/replace anti-vibration elements. |
| Cutting wheel does not stop at idle | Idle speed too high, clutch sticking | Adjust idle speed screw (LA) lower. Clean clutch drum and shoes. |
| Fuel/oil leak | Cracked fuel tank, damaged lines, leaking carburetor gaskets | Inspect visually. Replace damaged components. |
Refer to the official STIHL parts catalog for the TS 400 (PN 0000-350-4101) for complete exploded diagrams and part numbers. Major assemblies include:
Note: Always use genuine STIHL replacement parts to ensure safety and performance.
Critical fasteners must be tightened to the correct torque.
| Fastener | Torque (Nm) | Torque (ft-lb) |
|---|---|---|
| Cylinder Base Nuts | 20 Nm | 14.8 ft-lb |
| Cylinder Head Nuts | 20 Nm | 14.8 ft-lb |
| Flywheel Nut | 40 Nm | 29.5 ft-lb |
| Clutch Nut | 40 Nm | 29.5 ft-lb |
| Cutting Wheel Spindle Nut | 50 Nm | 36.9 ft-lb |
| Muffler Screws | 10 Nm | 7.4 ft-lb |
| Spark Plug | 25 Nm | 18.4 ft-lb |
STIHL Limited Warranty: Refer to the warranty card included with your product for specific terms and duration.
Service: Complex repairs should be performed by an authorized STIHL servicing dealer. They have the proper tools, training, and access to genuine parts.
Manual Updates: For the latest version of this service manual or technical bulletins, contact your STIHL dealer or visit the official STIHL website.
Support Contact: STIHL Incorporated, 536 Viking Drive, Virginia Beach, VA 23452. Customer Service: 1-800-467-8445. Website: www.stihlusa.com.