MS 391 - 50cm/20"

EXCELLENT CHAINSAW FOR HEAVY AGRICULTURAL USE

Features & functionality

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.

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.

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.

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.

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.

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.

Single-lever master control
All important functions such as start, choke, throttle and stop are operated via a single lever.

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%.

Tool free filler caps
Special catches on the fuel and oil tanks for easy opening and locking without the need for tools.

Product code: 1140 200 0741