stihl 066 parts manual pdf

The STIHL 066 is a professional-grade chainsaw known for its power and durability. This parts manual provides detailed diagrams, part numbers, and ordering information for the STIHL 066 chainsaw and its variants (e.g., 066 Magnum). It is an essential resource for servicing, repairing, and maintaining the saw to ensure optimal performance and longevity. Below are key sections covering parts identification, diagrams, ordering, maintenance, and safety.

Introduction & Model Identification

Identifies the STIHL 066 model range, serial number location, and major variants. Includes notes on part compatibility between different versions.

Model Variant	Key Identification	Notes
STIHL 066	Standard model, 91.0 cc engine	Base version
STIHL 066 Magnum	High-performance version, 91.0 cc	Enhanced power output
STIHL MS 660 (Modern Equivalent)	Successor model, similar architecture	Many parts are interchangeable

Serial Number: Located on the crankcase. Required for ordering correct parts.

Safety Parts & Critical Components

Lists safety-critical parts that must be replaced with genuine STIHL components to maintain safe operation.

1. Chain Brake Components: Band, handle, activation parts.
2. Throttle Control & Lockout: Throttle lever, interlock, springs.
3. Muffler & Heat Shields: Spark arrestor screen, deflector.
4. Anti-Vibration Elements: AV springs, buffers, mounts.

WARNING! Using non-genuine or worn safety parts can lead to serious injury or saw failure.

Engine Assembly & Cylinder Group

Detailed parts list for the engine block, cylinder, piston, and related components.

• Cylinder: Part number for cylinder with bore specifications.
• Piston & Piston Rings: Includes ring set and wrist pin.
• Cylinder Cover & Decompression Valve: Gaskets, valve assembly.
• Connecting Rod & Bearings: Crankpin bearing, rod assembly.

Note: Piston and cylinder should be replaced as a matched set for best performance.

Fuel System & Carburetor

Parts for the fuel tank, lines, filter, and carburetor (typically Walbro or Zama).

1. Carburetor Kit: Diaphragms, gaskets, needle valve, pump lever.
2. Fuel Lines & Filter: In-tank filter, supply and return lines.
3. Fuel Tank & Cap: Tank assembly, vented cap, seals.
4. Impulse Line: Connects crankcase to carburetor pump.

Tip: Always use fresh, clean fuel and replace fuel filters regularly.

Ignition System & Electronics

Components for spark generation and engine stopping.

Part	Function	Part Number Example
Ignition Module (Coil)	Generates spark for plug	1140 400 1300
Spark Plug	Bosch WSR6F or equivalent	STIHL 0000 400 1301
Stop Switch & Wiring	Grounds ignition to stop engine	Wiring harness, switch
Flywheel & Key	Magnets for ignition timing	Flywheel, Woodruff key

Chain Drive & Clutch Assembly

Parts for transmitting engine power to the chain.

• Clutch Drum & Sprocket: Rim sprocket or spur sprocket assembly.
• Clutch Shoes & Springs: Centrifugal clutch assembly.
• Bearing & Oil Seal: Crankshaft bearing and seal at clutch side.
• Chain Tensioner: Screw, adjuster, and pin for bar adjustment.

Maintenance: Inspect clutch springs for fatigue and sprocket for wear.

Guide Bar, Chain & Cutting Attachments

Components for the cutting system. Note: Bar and chain are wear items.

1. Guide Bar: Various lengths (e.g., 25", 32"). Part number includes pitch/gauge.
2. Saw Chain: STIHL 3/8" .063 gauge full-chisel or semi-chisel.
3. Bar Mount Pattern: STIHL 3005 (D009) for 066.
4. Chain Sprocket Nose: Replaceable tip for roller-nose bars.
5. Bar Nuts & Washers: Retaining nuts and chain cover washers.

Crankcase & Crankshaft

Major engine structural components.

Crankcase Halves: Right and left halves with bearing seats.
Crankshaft Assembly: Includes main bearings and seals.
Oil Pump & Drive: Automatic chain oiler, worm gear, adjuster.
Seals & Gaskets: Complete gasket set for engine rebuild.

CAUTION! Crankcase assembly requires proper sealing and torque specifications.

Starter Assembly & Recoil

Parts for the pull-start mechanism.

• Starter Housing: Plastic cover with rope guide.
• Recoil Spring & Pawls: Recoil spring, starter dogs (pawls).
• Starter Rope & Handle: Rope, knot, and plastic handle.
• Pulley & Spring Retainer: Rope pulley and spring retaining clip.

External Covers & Handles

External parts for protection and handling.

Cover/Handle	Description
Top Cover (Air Filter Cover)	Includes filter access and latch
Right & Left Side Covers	Clutch cover and muffler side cover
Front Handle	Wraparound handle with anti-vibration
Rear Handle & Tank Grip	Main handle with fuel tank
Chain Brake Handle Guard	Protective guard for front hand

Ordering Parts & Exploded Diagrams

How to use this manual to order parts. Each section corresponds to an exploded diagram with numbered parts.

1. Locate the assembly diagram for the needed component (e.g., "Engine Group - Figure 3").
2. Match the item number in the diagram to the parts list table below it.
3. Use the exact STIHL Part Number provided when ordering from a dealer.
4. Provide your saw's serial number to confirm part compatibility.

Official Support: For genuine STIHL parts, contact an authorized STIHL dealer or visit www.stihlusa.com.

Disclaimer: This manual is for reference. Repair should be performed by qualified technicians.