Stihl HS 81 T Parts Manual

The Stihl HS 81 T is a professional-grade hedge trimmer designed for demanding applications. This parts manual provides detailed diagrams, part numbers, and ordering information for the complete assembly, including the engine, cutting blade system, fuel system, ignition, and housing components. Below are key sections for identification, assembly groups, exploded views, and ordering.

1. Introduction & Safety 2. Model Identification 3. General Assembly 4. Engine Assembly 5. Cutting Blade Assembly 6. Fuel System Assembly 7. Ignition System Assembly 8. Housing & Handle Assembly 9. Part Number Index 10. Ordering Information 11. Warranty & Service

Introduction & Safety

This manual is intended for professional service technicians. Always refer to the official Stihl service manual for repair procedures. Use only genuine Stihl replacement parts.

Warning Symbol	Meaning
⚠️	Indicates a potentially hazardous situation which, if not avoided, could result in serious injury or death.
⚡	Risk of electric shock. Disconnect spark plug boot before servicing.
🔥	Hot surface. Allow engine and muffler to cool before handling.

WARNING! Always wear appropriate personal protective equipment (PPE) including safety glasses and gloves when handling parts or performing maintenance.

Model Identification

Locate the serial number and model designation on the machine's identification plate.

Model: HS 81 T
Engine Type: 2-stroke, single cylinder
Displacement: Refer to engine serial number for specific variant.
Cutting Blade Length: Standard length as per specification.

Note: Always provide the complete serial number when ordering parts.

General Assembly

Exploded view of the complete unit showing major component groups and their relationship.

Item 1: Upper Housing / Fan Cover
Item 2: Engine Assembly (see Section 5)
Item 3: Fuel Tank Assembly
Item 4: Rear Handle & Control Assembly
Item 5: Drive Shaft Housing
Item 6: Cutting Blade Assembly (see Section 6)
Item 7: Blade Guard

Engine Assembly

Detailed parts breakdown of the 2-stroke engine. Includes cylinder, piston, crankshaft, carburetor, and muffler components.

Ref. No.	Part Description	Part Number
5.1	Cylinder Complete	XXXX XXXX XXX
5.2	Piston Assembly	XXXX XXXX XXX
5.3	Crankshaft	XXXX XXXX XXX
5.4	Carburetor, Diaphragm Type	XXXX XXXX XXX
5.5	Muffler with Spark Arrestor	XXXX XXXX XXX
5.6	Rewind Starter Assembly	XXXX XXXX XXX

Note: Gasket sets must be replaced during engine overhaul.

Cutting Blade Assembly

Components of the double-sided reciprocating blade system, including blades, blade bolts, counter knives, and gear drive.

Upper Blade: Serrated cutting edge, includes mounting holes.
Lower Blade: Matches upper blade, reciprocates in opposite direction.
Blade Bolts & Nuts: Torque to specification.
Counter Knife: Stationary lower blade.
Drive Gear & Connecting Rod: Converts rotary motion to reciprocating.

WARNING! Blades are extremely sharp. Handle with heavy-duty gloves. Ensure machine is off and spark plug disconnected.

Fuel System Assembly

Parts for the fuel tank, fuel lines, filter, and carburetor linkages.

Fuel Tank: Polyethylene construction.
Fuel Cap: Ventilated.
Fuel Line (Supply & Return): Oil-resistant tubing.
In-Tank Fuel Filter: Replace annually.
Primer Bulb: For cold starting.
Choke Lever & Linkage: Controls carburetor choke plate.

Tip: Use only clean, fresh fuel mixed with Stihl-approved 2-stroke oil.

Ignition System Assembly

Components for engine spark generation and stopping.

Ref. No.	Part Description	Part Number
8.1	Ignition Module (CDI)	XXXX XXXX XXX
8.2	Spark Plug, Type XYZ	XXXX XXXX XXX
8.3	Stop Switch & Wiring Harness	XXXX XXXX XXX
8.4	Spark Plug Boot	XXXX XXXX XXX

CAUTION! Check spark plug gap before installation.

Housing & Handle Assembly

External covers, handles, vibration dampeners, and control levers.

Upper & Lower Housing Halves: Engine enclosure.
Rear Handle: Includes throttle trigger and lockout.
Front Handle / Loop Handle: Vibration-dampened.
Anti-Vibration Elements: Rubber mounts.
Debris Shield: Protects operator.
Label Kit / Decals: Safety and model information.

Part Number Index

Alphabetical list of common parts with reference to their section.

Air Filter: See Engine Assembly (5.x)
Blade Bolt: See Cutting Blade Assembly (6.x)
Fuel Cap: See Fuel System Assembly (7.x)
Starter Rope: See Engine Assembly (5.6)
Throttle Cable: See Housing & Handle Assembly (9.x)

Ordering Information

Contact an authorized Stihl dealer to order parts. Provide the model (HS 81 T) and serial number, along with the part number and description from this manual.

Online: Parts can be looked up via authorized dealer portals.

Phone: Contact Stihl USA at 1-800-GO-STIHL (1-800-467-8445).

Warranty & Service

Topic	Information
Warranty Period	Refer to the official Stihl warranty statement provided with the unit. Professional use may affect terms.
Authorized Service	Repairs should be performed by an authorized Stihl servicing dealer to maintain warranty and safety.
Technical Support	Available through your Stihl dealer.
Manual Updates	Check with your dealer for the latest version of this parts manual.

Disclaimer: Stihl reserves the right to make changes at any time without notice. Illustrations may not reflect the latest production version.

Service Network: Find a dealer at www.stihlusa.com