Selection Petrol chainsaws for forestry work

MS 661 C-M Petrol Chainsaw

Extremely powerful 5.4kW professional saw

Overview

Very powerful high-performance saw with advanced 2-MIX technology and STIHL M-Tronic (M). This electronic engine management system regulates the ignition timing and the fuel supply and automatically registers the external temperature for optimal engine performance, great acceleration and sustained maximum torque. Extremely robust and durable with low vibration levels. Designed for professional use within forestry and big timber harvesting. Supplied with rollomatic E guide bar, not rollomatic ES light as pictured.

You can find videos showing you how to fill your machine with fuel and oil, fit bars and chains and start your chainsaw here.

£1,464.00*

Versions

Price

* Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

The version(s) available in each country may differ from the above range and specifications; specific details may be subject to change without notice. Please ask your local STIHL Approved Dealer for further information.

Technical data

MS 661 C-M

Technical data

Technical data Value
Displacement cm³ 91.1
Power output kW/bhp 5.4/7.3
Weight kg 1) 7.4-7.5
Power-to-weight ratio kg/kW 1.4
System weight kg 2) 9.22 / 10.28 / 10.38
CO2 g/kWh 711
STIHL Oilomatic saw chain pitch/type 3/8" RS
Sound pressure level dB(A) 3) 105
Sound power level dB(A) 3) 118
Vibration values left/right m/s² 4) 6.9/5.6
Tank volume l 0.85
Speed at maximum power Um 9.500
Bumper spike Stahlkralle,Steel claw
Sprocket - number of teeth 7.7 Z
Cylinder Chrom,Chrome
Oil pump Adjustable,einstellbar
Filter HD2 filter,Patronenfilter HD2
Sprocket Chain sprocket,Ring sprocket,Ringkettenrad
Chain tensioning Lateral chain tensioning,seitliche Kettenspannung,Side chain tension
Anti vibration system Standard AV-System
Handle type Standard grip,Standardgriff
Filler cap Tool free filler cap,WTV werkzeugloser Tankverschluss
Chain pitch 3/8"
EPA Certified fuel consumption glh 0.751
EPA Certified fuel consumption l/h 2.841
Oil tank volume cm3 400

1) Without fuel, without bar and chain
2) Unfueled, with guide bar and saw chain
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

The version(s) available in each country may differ from the above range and specifications; specific details may be subject to change without notice. Please ask your local STIHL Approved Dealer for further information.

Features

MS 661 C-M

Standard features

  • Decompression valve Zoom
    Decompression valve

    The decompression valve is part of the easy starting system. The valve should be pressed before starting to reduce the compression pressure when starting, as well as reducing the effort needed to pull the starter rope. The decompression valve is semi-automatic; it must be pressed manually before starting, but then closes automatically.

  • 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.

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

    This fully electronic engine management system adjusts ignition timing and fuel metering in all operating modes. It also takes external conditions such as temperature, altitude and fuel quality into account. It ensures consistent engine performance, a constant maximum speed and superb acceleration. M-Tronic makes manual carburettor adjustments unnecessary. Thanks to electronic cold/warm start recognition, now there is only one start position on the combi-lever. The engine starts after fewer pulls and with no change of position, and can immediately accelerate up to speed - even after a cold start. M-Tronic also remembers the settings from the last time the tool was used. So when external conditions are the same, optimal engine performance is available every time you start up again.

  • HD2 filter Zoom
    HD2 filter

    The HD2 filter is made from polyethylene filter material with up to 70% finer pores than fleece and polyamide filters to trap even very fine dust. In addition, it is oil and water-repellent and thus very easy to clean. The PET-covered filter cartridge with quick-release lock enables the filter to be assembled and disassembled in next to no time, without using tools.

  • STIHL 2-MIX-Engine Zoom
    STIHL 2-MIX-Engine

    1-in-4 channel technology. The economical STIHL 2-MIX engine with 1-in-4channel technology features a high torque over a wide speed range. The chainsaw provides fuel savings of up to 20% compared to STIHL two-stroke engines in the same performance class without 2-MIX technology. Exhaust emissions are reduced by up to 50%.

  • Anti-vibration system Zoom
    Anti-vibration system

    Intense vibration at the handles of power tools can lead to long-term effects on blood vessels in the hands and arms. STIHL has therefore developed an effective anti-vibration system whereby the oscillations from the machine's engine are dampened which significantly reduces vibrations at the handles.

  • Compensator Zoom
    Compensator

    This controller in the carburettor prevents the fuel-air mixture getting richer as the air filter becomes clogged. The correct quantity of fuel is delivered to the carburettor depending on the quantity of air passing through the air filter. This keeps the fuel/air ratio in the combustion mixture constant and hence also the engine power. The filter doesn't need to be cleaned until an appreciable drop in power occurs.

  • Captive nuts Zoom
    Captive nuts

    When changing the cutting attachment, you will not risk losing the nuts on the sprocket. The MS 261 is the first STIHL chainsaw to be equipped with the captive nuts. A great advantage for all users.

  • Variable-displacement oil pump Zoom
    Variable-displacement oil pump

    Allows a precise, demand-based delivery of oil. It's possible to reduce oil production by up to 50% in the E position. For very long cutting attachments or very dry wood, an additional volume of oil can be added by the user. similar to illustration.

  • Side chain tensioner Zoom
    Side chain tensioner

    The tensioning screw can be found on the side of the chain saw through the sprocket cover. This removes the need for contact with the sharp saw chain.

  • Ematic chain lubrication system Zoom
    Ematic chain lubrication system

    The Ematic chain lubrication system ensures pinpoint lubrication of the saw chain links and guide bar rails. When used with STIHL OILOMATIC saw chain, it will provide maximum lubrication, longer wear and less oil consumption than conventional methods of chain lubrication. The Ematic system can reduce bar oil consumption by up to 50%.

  • STIHL ElastoStart Zoom
    STIHL ElastoStart

    STIHL ElastoStart reduces the shock caused by the compression of the engine during starting. The compression shock is taken away from the user's joints and muscles through a spring or rubber element in the starter handle.

  • Tool free filler caps Zoom
    Tool free filler caps

    Special catches on the fuel and oil tanks for easy opening and locking without the need for tools.

The version(s) available in each country may differ from the above range and specifications; specific details may be subject to change without notice. Please ask your local STIHL Approved Dealer for further information.

Cutting Attachments

MS 661 C-M

Cutting Attachments

    • Rollomatic ES Light Zoom
      Rollomatic ES Light

      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 data Value
    Bar length 50cm/20",63cm/25",71cm/28"
    Sprocket pitch 9.32mm/3/8"
    Number of teeth on the sprocket 11
    Pitch 3/8 Inch
    Groove width 1.6 mm
    Groove width 1.6mm/.063"
    Number of teeth 11
    Bar type Stern-RollomaticSuper-Light
    Bar connection 3.003

    Versions

    Price
    • Rollomatic ES Light, 3/8", 1,6 mm, 71 cm / 28" (MS 500i and MS 661 only) £132.00*

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Rollomatic ES Zoom
      Rollomatic ES

      The STIHL Rollomatic ES (STIHL Ematic Super) is composed of a solid and particuarly rigid bar with a bar nose which can be replaced entirely. It is therefore ideal for most demanding professional tasks and is used chiefly on heavy duty machines for felling and bucking. Elliptically fomed, angled oil holes increase the flow speed of the chain oil, delivering optimal lubrication and even longer service life for the guide bar.

    Technical data Value
    Bar length 50cm/20",63cm/25",75cm/30",90cm/36"
    Sprocket pitch 9.32mm/3/8"
    Number of teeth on the sprocket 11
    Pitch 3/8 Inch
    Groove width 1.6 mm
    Groove width 1.6mm/.063"
    Number of teeth 11
    Bar type Stern-RollomaticSuper
    Bar connection 3.003

    Versions

    Price
    • Rollomatic ES, 3/8", 1.6 mm, 75 cm / 30" (MS 500i and MS 661 only) £135.00*

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Rollomatic ES Zoom
      Rollomatic ES

      The STIHL Rollomatic ES (STIHL Ematic Super) is composed of a solid and particuarly rigid bar with a bar nose which can be replaced entirely. It is therefore ideal for most demanding professional tasks and is used chiefly on heavy duty machines for felling and bucking. Elliptically fomed, angled oil holes increase the flow speed of the chain oil, delivering optimal lubrication and even longer service life for the guide bar.

    Technical data Value
    Bar length 50cm/20",63cm/25",75cm/30",90cm/36"
    Sprocket pitch 9.32mm/3/8"
    Number of teeth on the sprocket 11
    Pitch 3/8 Inch
    Groove width 1.6 mm
    Groove width 1.6mm/.063"
    Number of teeth 11
    Bar type Stern-RollomaticSuper
    Bar connection 3.003

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Rapid Super (RS) Zoom
      Rapid Super (RS)

      High performance saw chain for professional applications with low vibration levels, smooth cutting behaviour, low chatter and extremely high cutting and borning performance.

    Technical data Value
    Pitch 3/8 inch
    Drive link gauge 1.6 mm
    Drive link thickness 1.6mm/.063"
    Chain pitch 9.32mm/3/8"
    Required File size 5.2mm / 13/64"

    Versions

    Price
    • Rapid Super (RS) 3/8", 1.6 mm, 91 drive links, 71 cm / 28" (MS 500i and MS 661 only) £51.55*

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Rapid Super (RS) Zoom
      Rapid Super (RS)

      High performance saw chain for professional applications with low vibration levels, smooth cutting behaviour, low chatter and extremely high cutting and borning performance.

    Technical data Value
    Pitch 3/8 inch
    Drive link gauge 1.6 mm
    Drive link thickness 1.6mm/.063"
    Chain pitch 9.32mm/3/8"
    Required File size 5.2mm / 13/64"

    Versions

    Price
    • Rapid Super (RS) 3/8", 1.6 mm, 98 drive links, 75 cm / 30" (MS 500i and MS 661 only) £57.20*

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Rapid Super (RS) Zoom
      Rapid Super (RS)

      High performance saw chain for professional applications with low vibration levels, smooth cutting behaviour, low chatter and extremely high cutting and borning performance.

    Technical data Value
    Pitch 3/8 inch
    Drive link gauge 1.6 mm
    Drive link thickness 1.6mm/.063"
    Chain pitch 9.32mm/3/8"
    Required File size 5.2mm / 13/64"

    Versions

    Price
    • Rapid Super (RS) 3/8", 1.6 mm, 114 drive links, 90 cm / 36" (MS 661 only) £67.00*

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

The version(s) available in each country may differ from the above range and specifications; specific details may be subject to change without notice. Please ask your local STIHL Approved Dealer for further information.

Accessories

MS 661 C-M

Accessories

    • Service Kit 16 Zoom
      NEWService Kit 16

      With Service Kit 16 for STIHL petrol chainsaws you can carry out simple maintenance work on your chainsaw yourself. Regular standard maintenance, such as replacing the air and fuel filters and the spark plug, increases the service life of your chainsaw. And because of this, you yourself can help to ensure that machine components and parts are protected from dirt and damage and that the motor of your chainsaw always works reliably and with optimum performance.

      Service Kit 16 for MS 661 includes the following components for standard maintenance:

      • HD2 air filter
      • Spark plug
      • Fuel filter

      The STIHL HD2 air filter is suitable for all operating conditions and can therefore be used universally. Thanks to its fine pores, it offers a very high filter quality and filters even the finest dirt from the intake air. By replacing the HD2 filter, the chainsaw motor is reliably protected against the ingress of abrasive dust. The performance is retained, the consumption is low and you can continue to start your STIHL chainsaw as easily as usual.

      In order to maintain performance, it is also recommended to replace the spark plug regularly. This is the basis for clean combustion in the engine. The fuel filter keeps the fuel free of foreign particles before it gets into the engine. In this way, it protects the engine and ensures an improved longevity. This must also be replaced regularly in order to function reliably.

      To replace the air filter and spark plug, it is best to use the practical combination wrench that you received with your STIHL chainsaw. A cardboard hook is integrated in the packaging of the service kit itself. This allows you to easily remove and replace the fuel filter. You do not need any additional tools.

    Technical data Value
    Suitable for 1) MS 661

    1) This service kit can only be used with the following machines

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • MotoMix Zoom
      MotoMix

      STIHL MotoMix is our patented premixed fuel, specially blended for ultimate performance. This 50:1 ready-mixed fuel is a combination of premium non-ethanol, high-octane motor fuel for all STIHL 2-stroke engines which gives you optimum performance, excellent cold start properties, maximum acceleration over the entire rpm range and perfect running characteristics even with a sudden rev change. With STIHL HP ultra premium oil for exceptional engine lubrication and extreme cleanliness, fully synthetic and biodegradable for optimal performance and long service life. User- and engine-friendly thanks to fewer emissions (free from ethanol; almost no olefins and aromatic compounds). Can be kept in storage for up to five years. Reliable top performance – STIHL 2-stroke engines and STIHL MotoMix are made for each other; all conceivable applications have been put through rigorous testing.

      Find out more about our MotoMix promotion here.


      Patent EP 2031043


    Technical data Value
    Octane number >95 RON
    Octane rating 93 MOZ
    Aromatic content 0.1 % Vol.
    Benzene content 0.03 % Vol.
    Sulphur content 3 mg/kg
    Shelf life up to 5 Years
    Density at 15°C 690 kg/m3
    Olefin content 0.1 % Vol.
    Vapour pressure at 40 °C 61 kPA
    Two-stroke oil content 1.8 % Vol.

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • ForestPlus chain oil Zoom
      ForestPlus chain oil

      Based on high-quality mineral oils, ForestPlus is suitable for use with all chainsaws, including harvesters. ForestPlus delivers reliable chain lubrication and no resin build up, even during prolonged down times.

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • HP Ultra 2-stroke engine oil Zoom
      HP Ultra 2-stroke engine oil

      Fully synthetic oil with exceptional lubrication properties. Burns with extremely low residue due to ash-free additive. Suitable for continuous use under the most demanding engine conditions. Performance class: JASO-FB, ISO-L-EGB. Fuel/oil ratio 50:1. Recommended for STIHL 4-MIX engines.

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

    • Varioclean Zoom
      Varioclean

      Water based, alkaline detergent specifically for dissolving and removing burnt-in resin and oil residue from your machine, and cleaning your tool’s housing, HD2 filter, wire mesh filter or PA filter. The detergent is biodegradable. Avoid contact with the eyes and keep out of reach of children.

      To use Varioclean, first wait for your machine to cool down. Then, spray it onto the surface of the part you are cleaning and leave it for a maximum of 5 minutes, so the cleaner is not allowed to dry. Then, wash it off with water and wipe with a cloth to dry. We recommend you wear safety glasses when doing this.

    Technical data Value
    Shelf life 3 Years
    Biodegradable Yes

    Versions

    Price

    * Manufacturer's recommended retail price updated as of July 2021. The manufacturer's recommended retail prices are subject to change without notice.

The version(s) available in each country may differ from the above range and specifications; specific details may be subject to change without notice. Please ask your local STIHL Approved Dealer for further information.

Documents

Owners manuals and safety brochures

Languages Date Link
manual icon en 03/03/2021