STIHL HT101 Pole Saw Service Manual

The STIHL HT101 is a professional-grade pole pruner designed for extended reach cutting of high branches. This manual provides comprehensive service, maintenance, and safety information for qualified technicians. It covers the HT101's two-stroke engine, cutting system, telescopic pole, fuel mixture requirements, and critical safety systems. Below are key sections for safety, specifications, maintenance procedures, troubleshooting, and parts identification.

Safety Information & Warnings

Essential safety instructions for servicing the STIHL HT101. Failure to follow these can result in serious injury or death.

WARNING! This manual is for trained technicians. Users should refer to the operator's manual for basic use.

Specifications & Technical Data

• Model: STIHL HT101 Pole Pruner
• Engine Type: STIHL single-cylinder two-stroke engine
• Displacement: 31.8 cc (1.94 cu. in.)
• Powerhead Weight: Approximately 7.7 lbs (3.5 kg)
• Maximum Pole Length: Extendable to [Specify max length, e.g., 12 ft]
• Fuel/Oil Mix: 50:1 ratio using STIHL HP Ultra oil and 89+ octane gasoline
• Guide Bar Length: Standard 10-inch or 12-inch (varies)
• Pitch/Gauge: 1/4" P .043" (or as specified)
• Ignition System: Electronic, capacitor discharge (CDI)
• Carburetor: STIHL Zama diaphragm carburetor

Component Identification

Key serviceable components of the HT101 powerhead and pole assembly.

1. Powerhead: Throttle trigger, throttle lockout, master control lever (stop switch, choke, fast idle), fuel cap, spark plug, muffler, starter handle.
2. Cutting Attachment: Guide bar, saw chain, sprocket, clutch drum, chain tensioner, chain brake assembly (hand guard, activation mechanism).
3. Pole Assembly: Telescopic tubes, internal drive shaft, coupling points, locking mechanisms, anti-vibration elements.
4. Fuel System: Fuel tank, fuel filter, fuel line, carburetor, air filter.

Maintenance Schedule

Recommended service intervals for optimal performance and safety.

Fuel System Service

Procedures for servicing the fuel tank, lines, filter, and carburetor.

1. Fuel Tank Draining: Use a hand-operated pump. Do not siphon by mouth.
2. Fuel Filter Replacement: Disconnect fuel line, remove old filter from inside tank, attach new filter, reconnect line.
3. Fuel Line Inspection: Check for cracks, brittleness, or leaks. Replace if damaged.
4. Carburetor Adjustment (H/L Screws): Initial settings: Turn H and L screws gently clockwise to stop, then open 1 turn counterclockwise. Fine-tune for smooth idle and acceleration.
5. Air Filter Service: Remove cover, clean foam filter in warm soapy water, dry, and re-oil with STIHL filter oil.

CAUTION! Use only STIHL-approved fuel mix. Old or contaminated fuel is a common cause of performance issues.

Engine Service (Carburetor, Ignition)

Servicing the engine's core components.

Spark Plug: Use specified resistor plug (e.g., BOSCH WSR6F). Gap: 0.020" (0.5mm). Check electrode condition.

Ignition Module (CDI): Test with appropriate tester per STIHL specs. Check kill switch wire continuity.

Muffler & Spark Arrestor Screen: Remove muffler cover. Clean carbon deposits from screen with wire brush. Ensure passages are clear.

Cylinder & Piston Inspection: Remove muffler to view piston through exhaust port. Look for scoring or excessive carbon. Deep inspection requires cylinder removal.

Cutting Attachment Service (Sprocket, Bar, Chain)

Maintenance of the cutting components.

1. Chain Sharpening: Use correct round file size. Maintain proper filing angle (typically 30°). File all cutters to equal length.
2. Guide Bar Maintenance: Clean bar groove. Dress bar rails with a flat file if burred. Flip bar regularly for even wear.
3. Sprocket Inspection: Check clutch drum sprocket for wear (hooking). Replace if worn. Lubricate with grease.
4. Chain Tension Adjustment: Loosen bar nuts. Adjust tensioning screw until chain is snug against bar bottom, but can be pulled around by hand. Retighten nuts.
5. Chain Brake Service: Inspect band for wear/cracks. Check activation mechanism and spring. Test function after reassembly.

Telescopic Pole & Drive Shaft

Service procedures for the extension pole and drive train.

• Pole Disassembly: Unlock sections. Carefully withdraw inner tube. Inspect for dents or bends.
• Drive Shaft Inspection: Check for kinks, broken welds, or worn universal joints. Lubricate joints with STIHL drive shaft grease.
• Coupling Points: Ensure male and female couplings are clean, undamaged, and engage securely.
• Anti-Vibration Elements: Inspect rubber dampeners in handles and between pole sections. Replace if cracked or hardened.

Tip: Keep drive shaft clean and lightly greased to prevent binding and excessive wear.

Troubleshooting Guide

Torque Specifications

Critical fastener torque values (in lbf-ft). Use a calibrated torque wrench.

• Cylinder Head Nuts: [Specify value, e.g., 160 in-lb]
• Spark Plug: 15-20 Nm (11-15 lbf-ft)
• Clutch: [Specify value]
• Guide Bar Nuts: Tighten securely, but do not overtighten.
• Muffler Bolts: [Specify value]
• Pole Coupling Bolts: [Specify value]

WARNING! Overtightening can strip threads or damage components. Undertightening can lead to failure.

Exploded Views & Parts List

Reference for ordering genuine STIHL replacement parts. Diagrams include:

1. Powerhead Assembly (Crankcase, Cylinder, Piston)
2. Fuel System Assembly (Tank, Cap, Lines, Carburetor)
3. Ignition & Starter Assembly
4. Clutch & Cutting Attachment Assembly
5. Telescopic Pole & Drive Shaft Assembly
6. Anti-Vibration Handle Assembly

Parts Ordering: Always use the specific part number from the current parts list for your serial number. Contact an authorized STIHL dealer.

Service Support: For technical assistance, contact STIHL Inc. at 1-800-467-8445 or visit www.stihlusa.com.