Stihl 1144-200-0324 MS661C-M Petrol Chainsaw 90cm/36"

The MS 661 C-M is built for professional forestry operators who regularly tackle large-diameter hardwood and high-volume timber harvesting where sustained, reliable power output is non-negotiable. At 5.4kW it sits at the top of the STIHL petrol chainsaw range, and its selection as the competition saw for the STIHL TIMBERSPORTS® series is a strong endorsement of its performance credentials under extreme cutting demands.

M-Tronic fully electronic engine management continuously regulates ignition timing and fuel metering in real time, automatically accounting for external temperature, altitude, and fuel quality to maintain optimum engine performance throughout the working day without manual adjustment. The result is strong, consistent acceleration and maximum torque that is sustained across a wide range of conditions rather than dropping off as circumstances change.

The 2-MIX engine uses four-channel cylinder technology to deliver the fuel-and-air mixture more efficiently into the combustion chamber, reducing fuel consumption and exhaust emissions by up to 70% compared to conventional 2-stroke engines — while maintaining high power output. The engine meets the strict EU Stage V emissions directive and is low-maintenance by design.

The STIHL Ematic system combines a compatible guide bar, Oilomatic saw chain, and controlled-delivery oil pump to direct chain oil precisely where it is needed, reducing oil consumption by up to 50% in the E position. Additional oil volume can be set easily for long guide bars or very dry wood conditions. The HD2 air filter uses a PET material with up to 70% finer pores than conventional fleece or polyamide filters, keeping even fine dust away from the engine for a longer service life and extended cleaning intervals. The carburettor compensator maintains consistent engine performance over time as the filter gradually loads, meaning cleaning is only required when a noticeable drop in performance occurs.

Starting is aided by a decompression valve that reduces compression pressure on the starter cord pull, protecting the start system and reducing the physical effort required. The combi-lever requires only a single start position, and automatically resets to the operating position when the saw is switched off for immediate warm restarts. Captive sprocket cover nuts prevent loss during chain changes, and the side-mounted chain tensioner allows fast, protected re-tensioning via the sprocket cover. The tool-free bayonet fuel cap allows quick, secure tank access, and STIHL's anti-vibration system uses buffer and spring elements to reduce handle vibration and operator fatigue during extended professional use.