Stihl MS 661 CM Forestry Petrol Chainsaw 36 inch Bar 91.1cc

Stihl MS 661 CM 5.4kW extremely powerful professional petrol chainsaw.

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.

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.

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.

Technical Specification:

• Displacement: 91.1 cm³
• Power output: 5.4/7.3 kW/bhp 
• Weight ¹⁾: 7.4-7.5 kg
• Power-to-weight ratio: 1.4 kg/kW 
• Weight ²⁾: 10.38 kg
• Bar length: 90 cm
• Bar length: 36 "
• CO2: 711 g/kWh 
• STIHL Oilomatic saw chain pitch/type: 3/8" RS
• Sound pressure level ³⁾: 105 dB(A)
• Sound power level ³⁾: 118 dB(A)
• Vibration values left/right ⁴⁾: 6.9/5.6 m/s² 
• STIHL Oilomatic saw chain pitch/type: 3/8"
• Tank volume: 0.85 l
• Speed at maximum power: 9,500 rpm
• Bumper spike: Steel claw
• Sprocket number of teeth: 7.7 Z
• Cylinder: Chrome
• Filter material: PET-fabric
• Oil pump: Adjustable
• Filter: HD2 filter
• Sprocket Chain: Ring sprocket
• Chain tensioning: Lateral chain tensioning
• Anti vibration system: Standard AV-System
• Handle type: Standard grip
• Exhaust: Standard muffler
• Filler cap: Tool free filler cap
• Chain pitch: 3/8"
• Carburettor: STIHL M-Tronic
• EPA Certified fuel consumption: 0.751 glh 
• EPA Certified fuel consumption: 2.841 l/h
• Oil tank volume: 400 cm³

1) Without fuel, without bar and chain
2) Without fuel, with bar and 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