MS 391

• 

  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.

• 

  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.

• 

  Controlled-delivery oil pump

  Different bar lengths, wood types and sawing techniques require different amounts of oil. The controlled-delivery oil pump allows the user to select just the right amount of oil for the job at hand.

• 

  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.

• 

  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.

• 

  STIHL anti-vibration system

  Precisely calculated buffer zones minimise the transfer of engine and saw chain vibrations to the front and rear handles. The chainsaw therefore runs noticeably smoother. This allows the user to save their strength and work longer.

• 

  STIHL Ematic System

  Compared to conventional bars without Ematic, the STIHL Ematic system reduces the consumption of chain lubricant by up to 50 %, depending on the type of wood and the cutting attachment used. This system comprises a STIHL Ematic or Ematic S guide bar, a STIHL Oilomatic saw chain and a variable-flow or reduced-flow oil pump. As a result, virtually every drop of chain lubricant is delivered to exactly the right spot.

• 

  Single-lever master control

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

• 

  Side-mounted chain tensioning

  Side-mounted chain tensioning makes it easy to tension the chain safely.

• 

  Tool free fuel caps

  Special caps to open and close the tank cap quickly, easily and without tools.

Additional features

• 

  STIHL ElastoStart

  Due to compression pressure, jerky stresses occur when starting internal combustion engines. The damping element in the ElastoStart special starter grip alternately absorbs and releases force according to the compression pattern. The result is smooth, even starting.

We present some Product Technology features in product technology .

• • 

    2-in-1 file holder

    Practical tool for quickly sharpening the teeth and depth gauge in a single step. Ideal for occasional users. For 1/4" P, 3/8" P, .325", 3/8" and .404" saw chains, integrated file tolerance compensation (only from STIHL).

  Versions

  • 2-in-1 file holder, 3/8" ø 5.2 mm
    Save and compare

• • 

    HP Super two-stroke engine oil

    Semi-synthetic oil with low-ash additives for clean low-smoke burning. 'Low-smoke oil' performance class: JASO-FD, ISO-L-EGD. Fuel/oil ratio: 50:1. Particularly recommended for STIHL 4-MIX engines.

  Versions

  • HP Super two-stroke oil, 1 l metering bottle
    Save and compare

• • 

    SynthPlus chain oil

    Semi synthetic high performance lubricant is made from high grade base oils (refined oils) which prevents resinification during prolonged downtimes. Outstanding protection against wear.

  Versions

  • SynthPlus chain oil, 5 l
    Save and compare

• • 

    DYNAMIC SPECIAL helmet set

    Well established helmet set with new visor system, high noise protection and anti-dazzle peak. EN 352, EN 397, EN 1731.

  Technical data	Value
  Ear protection	SNR 28 (H:35, M:26,L:16)
  Sound level	108 dBA
  Helmet material	ABS (G22)
  Inner fittings	4-Point
  Light penetration	75 %
  Weight	620,5 g

  Versions

  • DYNAMIC SPECIAL helmet set
    Save and compare

• • 

    FUNCTION chainsaw boots

    Entry level model made of high quality full grain leather, with high grip soles and breathable textile lining. Also protects against moisture, wear and abrasion. Protection according to EN 17249, protection class 1 (=^20 m/s) and EN 20345 S2.

  Technical data	Value
  Leg height	20 cm
  Weight 1)	1,9 kg
  Cut protection class	Class 1
  Size	39 - 47

  1) Approx per pair, using size 42
  

  Versions

  • FUNCTION chainsaw boots, size 43 / 9
    Save and compare