The MS 661 C-M delivers outstanding cutting performance to make it the new number one in its class for felling, trimming and all commercial and forestry applications. The MS 661 C-M is a rugged all-rounder equipped with STIHL’s environmentally friendly 2-MIX engine technology for less fuel consumption, less emissions and outstanding cutting performance. In addition the MS 661 C-M features a heavy duty (HD2) air filter system with a radial seal which keeps out fine dust particles combined with the compensator the MS 661 C-M can now be used for 20% longer than the MS 660 before a filter clean is required. The MS 661 C-M is fitted with STIHL’s M-TRONIC electronic engine management system which enables the saw to automatically adjust to varying fuel grades, changes in altitude and temperature and as there are no manual carburettor adjustments starting this saw is easier than ever before, simply push the start lever to the on position and pull.
Bar nuts held captive in the sprocket cover will not get lost when changing over the cutting attachment.
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.
Intense vibration at the handles of power tools can lead to longer-term effects of blood vessels in the hands and arms. STIHL have therefore developed an effective anti-vibration system where by the oscillations from the machines engine are dampened which significantly reduces vibrations at the handles.
STIHL ElastoStart reduces the shock caused by the compression of the engine during starting. The compression shock is taken away from the users joints and muscles through a spring or rubber element in the starter handle.
The decompression valve is part of the easy start-system. The valve should be pressed before starting in order to reduce the compression pressure when starting, as well as the effort needed to pull the starter rope. The decompression valve is semi-automatic, meaning that 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.