The Stihl MS391 chainsaw is a powerful 64.1cc saw with a 4.5 bhp power output. The Stihl MS391 is an easy-to-manage, high-torque chain saw for improved performance and user comfort when harvesting wood or cutting 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.
The Stihl MS391 is excellent for harvesting wood and cutting firewood. It is a redesigned model with a reduced weight of 200 grams. It has a new long-life air filter system, the economical 2-mix engine and a decompression valve for effortless starting.
What else will I need to buy with my chainsaw?
- 2-Stroke Oil.
We advise STIHL MotoMix® which is Stihl’s patented premixed fuel, specially blended for ultimate performance. Like a sports drink for your engine, this 50:1 mixture is a combination of premium non-ethanol, high-octane motor fuel and our highest-quality STIHL HP Ultra oil. Clean and convenient, MotoMix® eliminates the hassle of mixing your own 2-stroke engine fuel while providing superior performance and lubrication. STIHL MotoMix® contains no ethanol, allowing it to maintain stability for up to two years after the seal is broken – so it stays fresh in your equipment during long storage periods. MotoMix® is also made of non-aromatic fuel and fully synthetic, highly biodegradable engine oil.
- Chain Oil
Chain lubricant promotes smooth operation by keeping the chain clean and free-running on the guide bar.
- Optional Extras
Chainsaw files, replacement bars and chains, chainsaw safety equipment (PPE) and log saw horses. All available in store at Masseys.
Stihl MS391 Chainsaw Specification
Displacement: 64.1 cm³
Weight: 6.4 kg
Power-to-weight ratio: 1.9 kg/kW
Power output: 3.3 / 4.5 kW/bhp
Vibration levels left/right: 4.0/4.0 m/s²
Oilomatic saw chain pitch/type: 3/8″ Rapid Micro Comfort
Sound power level: 115.0 dB(A)
Sound pressure level: 105.0 dB(A)
Features of the Stihl MS391 Chainsaw
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.
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.
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%.
Purchased from Masseys – If your chainsaw was purchased from Masseys and it develops a manufacturing fault during the warranty period, simply return the chainsaw to store and our mechanics will repair the machine free of charge. A warranty repair is when the machine has failed because of improper material or workmanship, under normal use and maintenance.
Purchased online – If you chainsaw was purchased from elsewhere, then we charge an initial £29.99 inspection charge to look at the machine. This will be refunded if the fault is a warranty issue and when the manufacturer has processed and accepted the warranty claim in full. Warranty for non-Masseys customers is 4-12 weeks as we have a duty to ensure our own customers are prioritised first.