Direct product selection: Petrol chainsaws for forestry

MS 661 C-M

MS 661 C-M petrol-driven chainsaw: cutting-edge technology for forestry work


The competition chainsaw used in the STIHL TIMBERSPORTS® series. Big-timber saw for the toughest jobs in forestry. M-Tronic guarantees optimum engine performance at all times, with its single starting position and stop button function offering easy starting. Controlled-delivery high-performance oil pump for conveying high quantities of oil, HD2 filter with very good filter effect, economical 2-MIX engine.


Deviations from the product range and information provided here are possible, depending on the country. STIHL reserves the right to make changes to technical specifications and equipment.

Product versions

  • MS 661 C-M W MS 661 C-M W petrol-driven chainsaw: for high performance even in winter forestry use

Technical specifications

MS 661 C-M

Technical specifications

Technical specifications Value
Displacement 91,1 cm³
Power output 5,4/7,3 kW/PS
Weight 1) 7,4 kg
Power-to-weight ratio 1,4 kg/kW
Sound pressure level 2) 105 dB(A)
Sound power level 3) 118 dB(A)
Vibration level left/right 4) 6,9/5,6 m/s²
Saw chain pitch 3/8"
STIHL Oilomatic saw chain type Rapid Super (RS)

1) Without fuel, without bar and chain
2) K-factor according to DIR 2006/42/EC = 2.5 (dB (A))
3) K-factor according to DIR 2006/42/EC = 2.5 dB (A)
4) K-factor according to DIR 2006/42/EC = 2m / s ²

Deviations from the product range and information provided here are possible, depending on the country. STIHL reserves the right to make changes to technical specifications and equipment.


MS 661 C-M

Standard equipment

  • STIHL M-Tronic (FT) Zoom
    STIHL M-Tronic (FT)

    For a cold start, the STIHL M-Tronic only needs one start position on the combi-lever. After starting, you can immediately power up to full speed. The amount of fuel required is precisely calculated by the system and supplied as needed. Otherwise, start in position I as usual.

  • STIHL ElastoStart Zoom
    STIHL ElastoStart

    Due to compression pressure, jerky stresses occur when starting internal combustion engines. The damping element in the ElastoStart special starter grip alternately absorbs and releases force according to the compression pattern. The result is smooth, even starting.


    HIGHLY POWER-EFFICIENT. With the STIHL 2-MIX engine, you can reduce exhaust emissions and fuel consumption, and therefore operating costs. This 2-stroke engine is low-maintenance and uses fuel efficiently even at high power levels. Use a mixture of petrol and engine oil as fuel. The STIHL 2-MIX engine complies with the strict EU Stage V emissions directive.


    FOR RELIABLE OPERATION EVEN IN WINTER. Thanks to carburettor preheating, you can work reliably with your chainsaw even in winter. You can change the operation from summer to winter mode in just one simple step. In the winter setting, pre-heated intake air flows around the carburettor, preventing it from icing up.


    OIL CONSUMPTION BASED ON NEED. The controlled-delivery oil pump reduces your chainsaw’s oil consumption by up to 50%. To use it, simply select the E position. For very long cutting attachments or very dry wood, an additional oil volume can be set by the user.


    FOR SIMPLE AND SECURE RE-TENSIONING. Side-mounted chain tensioning allows for protected, easy and quick chain tensioning and replacement. The tensioning screw is inserted laterally through the sprocket cover.

  • HD2-FILTER Zoom

    INCREASES SERVICE LIFE. The HD2 filter protects your power tool’s engine against even the finest dust, ensuring a longer service life and reduced wear. The filter made from PET material has up to 70% finer pores than fleece and polyamide filters, and is also oil- and water-repellent. This also makes it easier to clean the filter. When needed, the filter cartridge can be easily replaced without tools.


    REDUCED MAINTENANCE. The compensator is a control system in the carburettor, which uses pressure compensation to ensure that engine performance, exhaust gas quality and fuel consumption remain virtually constant over a long period of time, despite increasing contamination of the air filter. You do not need to clean the air filter until there is a noticeable drop in performance. This means that you can work for a long time without maintenance.


    EFFORTLESS START-UP. The decompression valve makes it easier to start your power tool. When starting, you can allow some of the compressed mixture to escape from the cylinder by opening the valve. This protects the start-up system and reduces the amount of force required on the starter cord.


    FOR MORE PLEASANT WORK. Vibrations can occur when you put your power tools through their paces, and these are particularly noticeable in the grip area. The buffer and spring elements of the STIHL anti-vibration system reduce the transmission of engine vibrations to the handle area and therefore to your body. The result is that your power tool is more comfortable to hold and your work is much less tiring.

  • STIHL Ematic System Zoom
    STIHL Ematic System

    Compared to conventional bars without Ematic, the STIHL Ematic system reduces the consumption of chain lubricant by up to 50 %, depending on the type of wood and the cutting attachment used. This system comprises a STIHL Ematic or Ematic S guide bar, a STIHL Oilomatic saw chain and a variable-flow or reduced-flow oil pump. As a result, virtually every drop of chain lubricant is delivered to exactly the right spot.

  • Combi lever Zoom
    Combi lever

    As M-Tronic has electronic cold and warm start recognition, only one start position is needed on the combi lever. The exact amount of fuel is supplied on demand. You do not need to know about the status of your chainsaw and can apply full throttle straight away - even with a cold start. Because the saw is warmed up by optimum acceleration in a few seconds.


    PROTECTION AGAINST LOSS The nuts are attached to the sprocket cover in a captive manner. This makes it impossible for the nuts to fall off and get lost when the cover is removed.

  • Tool free fuel caps Zoom
    Tool free fuel caps

    Special caps to open and close the tank cap quickly, easily and without tools.

Deviations from the product range and information provided here are possible, depending on the country. STIHL reserves the right to make changes to technical specifications and equipment.


MS 661 C-M


      ROLLOMATIC ES LIGHT, 3/8", 1,6 MM

      Lightweight version of the STIHL Rollomatic ES, made from hard-wearing special steel. The hollow centre is cut out and then welded using a special laser process. This produces an extremely stable hollow body with a flexible outer and substructure. The result is a weight saving of some 30% compared with Rollomatic ES guide bars.

    Technical specifications Value
    Pitch 9,32mm/3/8"
    Groove width 1,6mm/.063"
    Number of teeth 11
    Bar length 71cm/28",80cm/32",90cm/36"


    • Length 71 cm / 28"

    • Filing kit Zoom
      Filing kit

      Includes file holder with round file, flat file and file gauge in a sturdy case.


    • 2-in-1 file holder Zoom
      2-in-1 file holder

      Practical tool for quickly sharpening the teeth and depth gauge in a single step. Ideal for occasional users. For 1/4" P, 3/8" P, .325", 3/8" and .404" saw chains, integrated file tolerance compensation (only from STIHL).


    • DYNAMIC Protect MS Zoom
      DYNAMIC Protect MS

      Made from cow hide leather, STIHL DYNAMIC Protect MS work gloves have an ergonomic curved design for better grip, higher comfort and reduced fatigue. An elastic cuff supports the wrist and prevents dirt or chips from entering the glove. Cut protection level Class 1.

    Technical specifications Value
    Cut protection class Class 1
    Elasticated or fitted cuffs Yes
    Lined Yes
    Waterproof no


    • DYNAMIC EXTREM helmet set Zoom
      DYNAMIC EXTREM helmet set

      Upgraded helmet set with adjustable ratchet and V5 visor system. Three-zone visor with very high light penetration. With UV indicator. EN 352, EN 397, EN 1731.

    Technical specifications Value
    Ear protection SNR 28 (H:35, M:26,L:18)
    Sound level 108 dBA
    Helmet material ABS (G 3.000)
    Inner fittings 4-Point
    Light penetration 60-70-80 %
    Weight 650 g
    FPA tested Yes


    • ADVANCE GTX trekking chainsaw boots Zoom
      ADVANCE GTX trekking chainsaw boots

      Special profile sole with very good grip. High-quality, water-repellent suede. With breathable and waterproof GORE-TEX® membrane. Additional water and wear protection provided by high-rise rubber edge. Highly absorbent, removable inner sole. Suitable for demanding, professional chainsaw users on hillsides and for tree maintenance. EN ISO 17249, cut resistance Class 2 (= 24 m/s).


    • Combination socket tool Zoom
      Combination socket tool

      For tensioning the chain and changing the chain, bar and spark plug. Width across flats: 19 (for MS 261 up), 19-13 (for MS 271, MS, 291, MS 311, MS 391), 19–16 (for MS 170, MS 171, MS 180, MS 181, MS 193 C, MS 211, MS 231, MS 241, MS 251), 16 and 13 ( for MS 150, MS 201, MS 201 T).


    • Multi-function tool Zoom
      Multi-function tool

      Practical, multi-function quality tool in a sturdy plastic case. 3.5 mm flat-blade screwdriver for carburettor adjustment and cleaning grooves, Torx® TX 27 screwdriver, nylon pouch with belt loop. Width across flats 19-13 for MS 271, MS 291, MS 311 and MS 391, width across flats 19-16 for MS 170, MS 171, MS 180, MS 181, MS 193 C, MS 211, MS 231, MS 241 and MS 251.


    • Multi function tool, size across flats 19 - 13

    • STIHL Smart Connector Zoom
      STIHL Smart Connector

      The STIHL Smart Connector forms the basis for using all STIHL connected functions. These functions can be used via both the STIHL connected App and the STIHL connect Portal. Once correctly attached to a STIHL power tool or another manufacturer’s power tool, the STIHL Smart Connector records operational hours while the machine is running, stores them and transmits them to your smartphone via Bluetooth as soon as it is within range. The data received in the STIHL connected App is transferred to the STIHL Cloud when there is an internet connection. The data is stored there in compliance with data protection regulations. The STIHL connected App and STIHL connected Portal allow you to access your power tool data at any time. STIHL connected opens up new avenues for professional users to obtain a convenient and transparent overview of their own power tool fleet. At the same time, STIHL connected provides information including operational hours, power tool status including reminders of overdue maintenance, the last known location, and whether or not the power tools are currently nearby. For professional users, this means improved digital fleet management, more efficient processes within companies, and even closer contact with STIHL dealers. Private users can also use the system to keep an eye on their power tools and carry out maintenance at the right time.

    Technical specifications Value
    Dimensions (l x b x h) 53 x 42 x 14 mm
    Signal range ca. 10 m
    Running time per battery charge ca. 1 Year
    Connectivity BLE 4,2
    Battery 3V CR 2.032
    Weight 20 g


    • Holder 1144 for STIHL Laser 2-in-1 Zoom
      Holder 1144 for STIHL Laser 2-in-1

      For MS 661 C-M, all design variants


    • Laser 2-in-1 Zoom
      Laser 2-in-1

      Felling direction indicator and cutting guide in one. For cutting short pieces of wood without complicated measuring, can be used as a felling direction indicator to check the cuts and felling direction, demonstration video on DVD. Choose the holder suitable for your chain saw.


Deviations from the product range and information provided here are possible, depending on the country. STIHL reserves the right to make changes to technical specifications and equipment.


Owners manuals and safety brochures

Languages Date Link
manual icon de / fr / it 14.08.2019