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Stihl – MS 391 – Petrol Chainsaw
MS391 (Stihl 2-MIX) 4.5hp petrol chainsaw with 16/18/20″ bar.
Easy-to-manage, high-torque chainsaw for improved performance and user comfort when harvesting wood or sawing firewood. High torque over a wide range of speeds. Up to 20% less fuel consumption and up to 50% lower emissions compared with the previous model without 2-MIX technology.
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Product Details
Standard Features
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.
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.
| Displacement cm³ | 64.1 |
| Power output kW/bhp | 3.3/4.5 |
| Power-to-weight ratio kg/kW | 1.9 |
| Weight kg 1) | 6.2 |
| Sound pressure level dB(A) 2) | 105 |
| Sound power level dB(A) 2) | 117 |
| Vibration values left/right m/s² 3) | 4/4 |
| STIHL Oilomatic saw chain pitch/type | 3/8" RM |
| Oil tank volume cm3 | 350 |
| Tank volume l | 0.60 |
The engine requires a mix of petrol and engine oil. Simply mix a Stihl 50:1 two-stroke engine oil with unleaded (95 octane) petrol. The simplest method is using a standard 5 litre fuel canister and to add 0.1 litres (100 ml) of Stihl HP 2 stroke oil, close and thoroughly shake the canister and the mix is ready to use.
For this machine we recommend either Stihl HP or Stihl HP Ultra engine oil.
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