MS 661 C-M Chainsaw

Standard features

• 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

  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)

  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

  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

  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

  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

  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

  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

  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

  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

  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

  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

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

• Service 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.

  Suitable for 0)	MS 661

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

  Versions	Price
  Service Kit 16	£18.00*	Save and compare
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• MotoMix

  STIHL MotoMix is our patented premixed fuel, specially blended for ultimate performance. This 50:1 mixture is a combination of premium non-ethanol, high-octane motor fuel and our highest quality STIHL HP Ultra oil. It also stays fresh in your equipment over extended storage periods.

  Shelf life Years	up to 5

  Versions	Price
  MotoMix 5 l	£20.00*	Save and compare
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• 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
  ForestPlus chain oil - 5 l	£19.96*	Save and compare
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• 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
  HP Ultra 2-stroke oil - 1 l (for 50 l) metering bottle	£27.30*	Save and compare
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• 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.

  Shelf life Years	3
  Biodegradable	Yes

  Versions	Price
  Varioclean - 500ml	£10.20*	Save and compare
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