MS 391 Petrol Chainsaw

MANUAL DECOMPRESSION:
EFFORTLESS START-UP. The decompression valve makes it easier to start your tool. When starting, you can allow some of the compressed mixture to escape from the cylinder by opening the valve. This protects the start-up system and reduces the amount of force required on the starter cord.

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.

LONG-LIFE AIR FILTER SYSTEM FOR CHAINSAWS:
EXTENDED FILTER SERVICE LIFE. Pre-separation routing removes coarse, larger particles from the airstream before they can reach the actual filter. The HD2 filter keeps even fine dust away from the engine, ensuring a long engine service life, long cleaning intervals and easy maintenance of your chainsaw. When we refer to a long-life air filter system in chainsaws, this exclusively describes models that have pre-separation routing and an HD2 filter. With this system, you benefit from a significantly longer filter service life compared to conventional air filter systems.

COMPENSATOR:
REDUCED MAINTENANCE. The compensator is a control system in the carburettor, which uses pressure compensation to ensure that engine performance, exhaust gas quality and fuel consumption remain virtually constant over a long period of time, despite increasing contamination of the air filter. You do not need to clean the air filter until there is a noticeable drop in performance. This means that you can work for a long time without maintenance.

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.

SIDE-MOUNTED CHAIN TENSIONING:
FOR SIMPLE AND SECURE RE-TENSIONING. Side-mounted chain tensioning allows for protected, easy and quick chain tensioning and replacement. The tensioning screw is inserted laterally through the sprocket cover.

STIHL EMATIC SYSTEM:
REDUCES OIL CONSUMPTION. The STIHL Ematic system comprises a STIHL Ematic or Ematic S guide bar, a STIHL Oilomatic saw chain and a controlled-delivery oil pump. It ensures that the chain oil gets to where it is needed for lubrication. This allows you to reduce oil consumption by up to 50%. If you often work in dusty conditions or if you use long guide bars, you can quickly and easily increase the oil quantity at any time with the new oil pump system.

TOOL-FREE FUEL CAP FOR OIL AND FUEL TANKS:
QUICK AND EASY TO USE. With tool-free fuel cap, you can open and close oil and fuel tanks in just a few simple steps, thanks to a bayonet closure.