The MS 661 is an obsolute monster have a saw at 7.4 kg and 91cc output its built for the toughest of jobs in forestry.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.
- Reduced-emission engine technology:2-stroke engine with stratified charge. A fuel-free layer of air is created between the burned charge in the combustion chamber and the fresh charge in the crankcase, reducing the amount of fuel lost during the charge cycle. This results in more power with a lower weight, up to 20% lower fuel consumption than regular 2-stroke engines and significantly reduced exhaust emissions.
- 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.
- STIHL ElastoStart reduces the shock caused by the compression of the engine during starting.
- 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.
- 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%.
- Tool free filler caps:Special catches on the fuel and oil tanks for easy opening and locking without the need for tools
- 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.
- Captive Nuts The nuts on the chain sprocket cover will not get lost when changing the cutting attachment, due to their captive nature ensuring they are held in the housing. The MS 261 is the first STIHL chainsaw to be fitted with captive nuts.
- M-tronic No matter if you’re just starting up, working away or restarting your chain saw after a break, M-Tronic takes perfect control of ignition timing and fuel dosage whatever the operating status, and with electronic precision. It even takes account of external conditions like temperature, elevation and fuel quality. Letting you get off to a perfect start so you can concentrate on the job at hand – whether you’re felling, pruning or bucking.The cornerstone of M-Tronic technology is its control unit featuring a microprocessor, electronic temperature recognition and ignition system. The microprocessor represents the “brains” of M-Tronic. All relevant information on the status of the tool feeds into this. The result: an electronically precise supply of fuel – taking operating status and external conditions into account – means you will always benefit from optimal engine performance. It also saves you time and energy since you no longer have to worry about manual carburetor adjustments.
- 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.