Stihl MS 251 Chainsaw

STIHL MS 251: High-Torque Performance for Heavy Firewood & Timber Processing

The STIHL MS 251 is a high-performance petrol chainsaw engineered for farmers, landowners, and domestic users who require professional-grade cutting power for processing firewood, felling small timber, and site maintenance. Powered by a 45.6 cc STIHL 2-MIX engine delivering a robust 2.2 kW (3.0 bhp) output, this mid-range powerhouse utilizes stratified charge technology to cut fuel consumption by up to 20% and reduce exhaust emissions by 70% compared to traditional two-stroke powerheads. Weighing just 4.8 kg (bare tool), the MS 251 boasts an exceptional power-to-weight ratio paired with an advanced AV (Anti-Vibration) steel-spring system to minimize operator fatigue during extended cutting sessions. Built with a pre-separation air filtration system and a compensator carburetor that maintains consistent performance even as debris accumulates, the MS 251 combines rugged durability with effortless single-lever operation for demanding off-grid wood-cutting tasks.

Exclusive Architectural & Engineering Specifications

• High-Torque 2-MIX Stratified Charge Engine: The 45.6 cc engine creates a fuel-free air cushion between the burned charge and the fresh fuel-air mix in the crankcase, maximizing combustion torque while meeting stringent emissions standards.

• Pre-Separation Centrifugal Air Filtration: Air drawn into the engine is swirled centrifugally to eject larger dust particles before reaching the round cartridge filter, drastically extending air filter life and service intervals.

• Intelligent Carburetor Compensator: Automatically maintains the exact fuel-to-air mixture ratio even as the air filter becomes clogged with sawdust, preventing loss of engine RPM and ensuring steady power under load.

• Steel Spring Anti-Vibration Buffer System: Uses tuned steel springs rather than basic rubber mounts to isolate engine oscillations, achieving low handle vibration levels ($3.9\text{ m/s}^2$) for reduced risk of HAVS.

• Single-Lever Master Control Matrix: Cold start, choke, throttle lock, and run/stop functions are managed via a unified master control switch for streamlined cold starting.

• Ematic™ Controlled Chain Lubrication: Directs targeted chain oil flow precisely to the guide bar rails and saw chain drive links, reducing oil consumption by up to 50% when paired with STIHL Oilomatic® chains.

• Tool-Free Bayonet Tank Caps: High-durability fuel and bar-oil caps feature flip-up locks for quick, toolless refilling on the job site without risking cross-threading or leaks.

• Side-Mounted Chain Tensioning Access: The tensioning screw is accessed through the sprocket cover on the side of the saw, keeping hands away from the sharp saw chain and bumper spikes during adjustments.