Very light, handy and powerful professional chain saw. The electronic self-tuning engine management system means that the fuel supply is electronically controlled and the machine automatically adapts to operating and ambient conditions, ensuring optimal engine performance every time. The memory function remembers previous operating conditions and allows you to restart quickly after an extended break. With easy-clean HD2 filter, controlled-delivery oil pump and practical features such as a stainless steel muffler, captive nuts on the sprocket cover and monocoque cover with three quick release fasteners. The 2-MIX technology in the innovative STIHL MS 261 C-M ensures up to 20% less fuel consumption and up to 50% emissions reduction compared to the same power STIHL two-stroke engines without 2-MIX technology.
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.
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.
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.
Advanced combustion technology
Four overflow channels swirl the fuel-air mix before ignition, allowing for optimum combustion and highly efficient performance. The result is lower fuel consumption and high torque across a broad rpm range.
Pre-separation air filtration system
STIHL long-life air filtration systems with pre-separation achieve perceptibly longer filter life compared with conventional filter systems. Air drawn in is swirled. The larger, heavier particles are ejected. The pre-cleaned air is routed to the air filter via the pre-separator duct.
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.
Carburettor heating (V)
By changing the chain saw from summer to winter operation, the intake air is pre-heated over the engine fins. This ensures that the carburettor does not ice up and you can continue working in freezing temperatures.
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.
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.
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.
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%. Side chain tensionerZoom
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.
Displacement cm³ 50.2
Weight kg 1) 5.2
Power-to-weight ratio kg/kW 1.8
Power output kW/bhp 2.9/3.9
Recomm. max. bar length cm 45
Vibration levels left/right m/s² 2) 3.5/3.5
Sound power level dB(A) 3) 116
Sound pressure level dB(A) 4) 104.0