MS 391 - $579.95 DSRP SAVE $30.00 on select models


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Our top-of-the-line chainsaw for farm and ranch.

With an advanced low-emission engine technology, the STIHL MS 391 mid-range chainsaw improves fuel efficiency by up to 20% compared to previous models. The new air filtration system requires fewer filter changes, allowing for longer run times. Improved fuel efficiency and fewer filter changes save you time and money.

Print Spec Sheets
MS 391 Specifications
DISPLACEMENT 64.1 cc (3.9 cu. in.)
ENGINE POWER 3.3 kW (4.4 bhp)
POWERHEAD WEIGHT 6.2 kg (13.67 Ibs.)
FUEL CAPACITY 600 cc (20.3 oz.)
CHAIN OIL CAPACITY 350 cc (11.8 oz.)
GUIDE BAR LENGTHS (Recommended ranges) 40 to 50 cm (16" to 20")
STIHL recommends #3624 (33 RS3 72) OILOMATIC® saw chain and 20" 3003 008 8921 Ematic™ guide bar combination. The actual listed guide bar length can vary from the effective cutting length based on which powerhead it is installed on.
Model Features
  • Zoom
    Reduced-Emission Engine Technology - Caring for Nature
    The STIHL Inc. “Caring for Nature” seal identifies its powered products that are more environmentally conscious, producing zero or low exhaust emissions. STIHL Inc. defines “low exhaust emissions” as being cleaner than EPA and/or CARB exhaust emission standards.

    More Information

Standard Features
  • Zoom
    Common Features for Chainsaws
    View the features common to many STIHL chainsaws.
  • Zoom
    Pre-Separation Air Filtration System
    This time-saving technology boosts the efficiency of the engine’s filter system, doubling the time between air filter cleanings. Air drawn into the engine is first separated via centrifugal force, ejecting the heavier dirt particles before being routed to the air filter. This pre-separation means less dirt to be captured by the air filter, resulting in less frequent cleaning and maintenance.

    More Information

  • Zoom
    Anti-Vibration System
    STIHL has developed a system for minimizing the vibration levels of handheld outdoor power equipment. The STIHL anti-vibration system helps reduce operator fatigue and provides a more comfortable working experience.
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    IntelliCarb™ Compensating Carburetor
    The IntelliCarb™ Compensating Carburetor is designed to automatically adjust the air/fuel ratio when the air filter becomes restricted or partially clogged and maintains the engine’s correct RPM. IntelliCarb™ uses air from the clean side of the air filter to control the diaphragm and flow of fuel. As the air filter becomes dirty and less air is available for the carburetor, the IntelliCarb™ system adjusts the fuel flow to compensate for the decrease in air flow. This is in contrast to typical carburetors that utilize this air from the “dirty” side of the air box.
  • Zoom
    Side-Access Chain Tensioner
    The side-access chain tensioner makes it much more convenient for the user to adjust the saw chain with a bar wrench as opposed to the typical location of the guide bar adjustment screw.
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    Toolless fuel and oil caps with retainers
    Simply lift the lever and twist the caps to remove or tighten. There‘s no need to use a tool to tighten or loosen.

Important Information
WARNING! The occurrence called “kickback” can cause serious or fatal injury. Always read the instruction manual carefully before using your saw. STIHL uses a green and yellow color-coding system to help you select a powerhead, bar and chain combination that complies with the kickback requirements of ANSI Standard B175.1 (gasoline-powered saws) and §30 of UL 1662/ ANSI Standard B175.1 (electric chainsaws). Ask your STIHL dealer about safe operating procedures and the advantages of the STIHL Quickstop® chain brake, STIHL Quickstop® Plus (Q) additional chain braking feature, STIHL reduced kickback bars and STIHL low-kickback saw chains.

STIHL recommends the use of green reduced kickback bars and green low kickback chains on all STIHL chainsaws.
* The actual listed guide bar length can vary from the effective cutting length based on which powerhead it is installed on.
Note: STIHL recommends use of fuel with no more than 10% Ethanol content. Using fuel with greater than 10% Ethanol content may cause damage to your equipment and may void your STIHL warranty. Learn More…
WARNING! Improper use of any power tool may cause serious or fatal injury. Read, understand and follow carefully the operating and safety instructions in your instruction manual before using such products.

STIHL products sold through U.S. STIHL Dealers are for distribution in the United States only.
Click to view the STIHL Limited Warranty Time Periods
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    Complete Filing Kits
    Kits available for the following chain types: STIHL PICCO Mini; 1/4" pitch chain; .325" pitch chain; 3/8" pitch chain; .404" pitch chain.
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    3/8 PMN 9.32 5/32 4.0 0811 411 8073

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For Your Safety
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    Performance Zip Chaps - 6 Layer

    The Performance Zip Chaps - 6 Layer provides a full wrap-around protection for a user’s lower leg area and are made to stand up to daily wear and tear. The outer material is crafted from durable orange Cordura® nylon fabric, an all-weather material used in a range of premium outerwear brands. Inside, the chaps feature six layers of Avertic® Pro by Engtex® cut retardant material, designed to reduce the risk or severity of injury in the event of contact with the rotating saw chain on a gasoline-powered chainsaw. For extra convenience, the chaps feature rows of zippers that run along the entire inseam of the chap, helping to ensure a comfortable fit that is easy to put on and/or remove. Visit our Dealership to see these chaps in person.

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    Durable and hardworking, STIHL Pro Mark™ Dynamic Gloves deliver professional-grade hand protection. The palm and inner fingers are made of full grain tanned leather, so you can work with comfort without sacrificing a firm hold. Featuring multiple layers of cut-retardant materials – Avertic Pro and Dyneema fabrics by Engtex® – these gloves will help deliver protection without compromising the dexterity you need while operating a chainsaw. Accented with an orange rip-stop nylon backing, these dynamic gloves offer style and protection. Water repellant, breathable and featuring a Velcro wrist closure, STIHL Pro Mark™ Dynamic Gloves are as ready for the woods as you.
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MS 391 is rated 4.4 out of 5 by 294.
Rated 4 out of 5 by from Great saw and great buy I got the ms391 love the saw great power not heavy at all. Very happy with it. The only downside I saw to the saw is it is hard to start. Don’t know if it me or the saw. Other then that I would recommend the ms391 to anyone you will not be disappointed. Keep up the great work Stihl
Date published: 2018-05-25
Rated 5 out of 5 by from Cuts very well. Smooth running, powerful. I'm pleased so far. The best chainsaw I've ever used, hand down. There is no substitute for a stihl.
Date published: 2018-05-19
Rated 5 out of 5 by from really ...I own 6 chainsaws use mine all the time. run ethanol free gas. crankem and cut thousands of pieces of firewood.064...039. ms 310 ms 362 occasional 250 and a 170. become quite the home professional. clean em. dont abuse them.
Date published: 2018-05-17
Rated 5 out of 5 by from Great from the beginning. I have had some saws that I bought from the box stores but they did not seem to hold up. I need to deal with 2 or 3 large trees every year on my wooded lot so I took a recommendation from someone and decided to try the Stihl saw. I was able to clean up two downed trees over the past couple of weekends with no issue. Great saw.
Date published: 2018-05-07
Rated 2 out of 5 by from if it starts it is good my brother boutht this and keeps it at my farm where he comes down to help out. He has had it in the shop 3 times (each time they say nothing is wrong) - takes forever to fire thhis puppy up. 85% of the time it floods then wait an hour and hope it doesn't flood again.I am heading to the logging store and getting a Husquarna and telling my bro to take this piece of crap off my farm.BTW - when it will start it cuts thru a log like butter
Date published: 2018-05-05
Rated 5 out of 5 by from Great saw Love this saw its my largest saw in my arsinal carry. Used to have the magnum but generally perfer this 391 due to weight. It cuts like a champ and after long continuous use the filter doesnt clog bogging the saw down. Its actually my second favorite behind my top saw.
Date published: 2018-05-04
Rated 5 out of 5 by from Wow!, What a great saw! I recently bought a MS 391 chain saw. This was after my 42 year old Stihl saw completely died. The 391 is a fabulous piece of equipment! It came with a 28" bar which I needed for cutting juniper on my property. It cut even the big trees with ease. One of the first things that jumped out to me was the run time of the saw. One tank of gas would last about 2and1/2 times as that of my old saw. The 28" bar allowed me to reach in and cut the trunks of the trees with ease. The weight of the saw is reasonable, this being said, I can cut for an extended period of time and not have my back hurt as was the case with my old saw. I should have bought a new saw sooner!
Date published: 2018-05-04
Rated 2 out of 5 by from Chain problem Whenever the chain leaves the bar, the chain guides get burrs, that make it impossible to replace the chain back into the bar without grinding several of the guides to remove the burrs. It appears that the STIHL chain steel is either too soft for the bar, or the bar is too hard for the chain steel.It is a pain to remove the bar and chain every time the chain comes off the bar.
Date published: 2018-05-03
Rated 5 out of 5 by from Accountability with a chain Play time should exceed work time and this MS391 turns work into play; makes quick use of the power to weight ratio on trees and logs that need clean cuts, VERY DEPENDABLE, a little pricey but I want this to work on my remote property without guesswork and it does!
Date published: 2018-05-02
Rated 5 out of 5 by from strong motor This is one “bad saw” saw the task at hand was the removal of the remains of two melaleuca trees estimated at about 60 years of age that had been struck by lightning. Commonly known as a paper tree by the way the bark sheds. However, it is not a soft wood tree in fact the core is an extremely dense hard wood known for dulling cutting chains fast and with being struck by lightning the sap was crystalized into a tuff resin further compounding the task. In addition, the trees were completely encrusted with a species of Indian banyan tree that roots it self into the bark of a tree completely strangling around the entire trunk of both trees and produces a thick milky in appearance gummy sap know for clogging the cutting chain of the saw. The first task was to cut off the branches between 6-8 in. dia. That immediately trashed the Home Depot throw away saw we had laying around. Clearly evident by the way we could hear the piston and rod shatter a sound all in its’ own. The main trunk with all the Banyan growth measured in dia. 36in. x 48 in. With the saw being new and this being the first task we took it easy after a low rpm warm up and equipped with a carbide toothed chain (another bad dude in itself) we made our first cut into the main trunk no problem at all and at only half throttle it went right through fast we couldn’t believe it !!!! We all looked at each other like “WOAH DID YOU SEE THAT!!!!” Totally awesome!!!! One cut after another again and again not even bogging down once. AT ONLY HALF THROTTLE!!!! What a saw we named it the terminator.
Date published: 2018-04-29
Rated 5 out of 5 by from 391 I love this saw and the only problem I have is . I can’t find a case to put it in . Everyone that Stihl has pushes down on the break and that is not good . There is 2” and you have two push that much down not good . If there is any suggestions please let me know.
Date published: 2018-04-27
Rated 5 out of 5 by from Awesome saw Bought this saw a few months ago and had a 28 in bar and a half skip chain put on it. I used it to cut some big oaks and it worked great. I would recommend it to anyone who has large trees to drop!
Date published: 2018-04-25
Rated 3 out of 5 by from Won't run Bought this saw yesterday, ran fine at the dealer. Went to use it on a job made 3 cuts, ran amazing. Then wouldn't start, pulled and pulled and pulled and nothingNot good for what I paid for this
Date published: 2018-04-23
Rated 5 out of 5 by from Starts First Pull Every Time! I bought my 391 used and it has quickly become my favorite saw over my 362 or 460. For some reason this saw starts first pull every time hot or cold no matter how long its been sitting! Now Ive probably jinxed myself and it will never start again. I run a 25” bar and consider it a perfect length for the saw. I vote the 391 to be the most saw for the money.
Date published: 2018-04-18
Rated 5 out of 5 by from Very powerful I just bought this saw after using and echo cs520 for the last 15 years. I finally got tired of fighting with the wood I'm cutting and decided to get enough power to get the job done. This saw is much more powerful that the 50cc echo. It is heavy so it would not be the best saw to use for tree trimming or overhead work. I am a carpenter so I work with tools all day long. But put this bad boy to work on a felling a tree or bucking up big trees for firewood and boy is it your friend. I could bog the echo down easily by leaning on the saw. This one can take my weight and keep going. I am cutting red oak and maple. I can't speak to reliability but it seems like a very well made saw. If you want to spend the whole day out in the yard puttering around, this might not be for you. If you want to get it done, I highly recommend this saw.
Date published: 2018-04-01
Rated 5 out of 5 by from It's a monster! I put a 25" bar on mine, and use it in my granberg chain saw mill. Works great. Plenty of power. I use a ripping chain when using the saw mill.
Date published: 2018-03-31
Rated 5 out of 5 by from Lots of power I am extremely happy with how much power this saw has. This is the reason why I went with this saw and I am very pleased.
Date published: 2018-03-29
Rated 5 out of 5 by from Best balance of size vs. cost I've been heating with wood for seven years using my inherited Sears Craftsman saw (60 cc, 18" bar, heavy as lead) that dad bought back in 1980. Enough is enough! I wanted an upgrade and decided this was the saw for me. What a great saw! I'm running a 25" bar with chisel chain on wet hardwoods and dead Locust trees which are hard as concrete and throw sparks. The MS391 has the power to pull an aggressive chain grind through the tough stuff. It's also pretty easy on the fuel consumption which increases my cutting time and saves money over the long haul. It starts within 5 pulls hot or cold and idles smoothe. This is my second season using this beast and I've upgraded it with bigger felling dogs. My next upgrade will be a 36" bar with skip tooth chain for cutting the really big trees that seem to get blown down in the spring storms every year. Needles to say the huge power increase and weight reduction over my old Sears has made me fall in love with this saw. Now it's time to buy a gas powered splitter and retire the old splitting maul.
Date published: 2018-03-26
Rated 1 out of 5 by from First stihl saw.... and last! Bought a 391 because it was the largest farm/ranch saw made by Stihl. Purchased to cut firewood. I used this unit to cut about 4 cords before it would not start. The cylinder and piston were essentially destroyed. Fuel meeting octane requirements was used in addition to Stihl 2 cycle oil. I also exsclusively use ethanol free fuel in 2 cycle engines. Unit was poorly made with badge plate falling off after 1st use. Pull rope broke several times until it was replaced with aftermarket unit. Retaining screws to hold cover on would loosen and fall out despite tightening them properly with torx bit. Oiler was erratic and prone to clogging. The dual bar nut and tensioning system worked well and was easy to use. Fuel economy was good for a saw this size and the caps for oil and fuel are the best I have seen. Starting after running out of fuel was very difficult. Power was a disappointment and I had to change the 25" bar the saw came with for 1st a 20" then an 18". I have used older model Stihl saws in the past and they were beasts cutting wood and ran like a top hour after hour. This saw does not meet those standards.
Date published: 2018-03-17
Rated 5 out of 5 by from Great Saw Awesome power never had a issue very reliable I've had mine for 3 years and couldn't ask for anything more
Date published: 2018-03-14
Rated 5 out of 5 by from How can they sell this saw for so cheap! To say I am impressed with this saw is an understatement. I have been cutting trees for a long time and had many different brands. I always thought Stihl was way to expensive, I was wrong. I bought a 180 about a month ago I was so impressed I went back for this monster when my old echo proved unable to efficiently cut the huge trees an ice storm.dropped all over our farm. This saw is a beast! It cuts big hickory trees like they are pine. It's just unbelievable how much power thia saw with a 24 in blade has. The dealer has been fantastic very good people to deal with. If your thinking about this saw you will not be disappointed.
Date published: 2018-03-13
Rated 5 out of 5 by from Best chainsaw ever had! Love this chainsaw, had several but none compared to the MS391. Lots of power, easy to use. 20in bar, I’ve cut 24in across oaks like butter. Do get the 2 in 1 file, to keep teeth sharp, you won’t have any problems.
Date published: 2018-03-09
Rated 1 out of 5 by from Stihl will not honor their warrenty Less than 90 days after purchasing a new ms391 the clutch let go. stihl would not honor their warrantee. I was told that is was caused by me running the saw with the brake on, or a really dull chain. Both of which are wrong. If it were possible to run the saw with the brake engaged, that doesn't say much about their saw brakes.
Date published: 2018-03-05
Rated 5 out of 5 by from Exactly what I have come to expect from Stihl This is my 3rd Stihl Chainsaw. I have an O41 Farmboss, an O36 and now an MS391. I have to say that this saw is impressive. It handles like my O36, but cuts like the O41. Plenty of power for a 20" bar, so if it is like the O41 it would probably handle the 24" like it wasn't even there. To be honest, I had to hold it back as it was almost too aggressive. Easy to start like all of my saws. Very well worth the money.
Date published: 2018-03-02
Rated 5 out of 5 by from This saw is a workhorse The 391 is a good priced saw with plenty of power. Power to weight ratio is great.
Date published: 2018-03-01
Rated 4 out of 5 by from Great Product Great saw, I have been very pleased so far. More importantly I was very pleased with the customer service and professionalism of the crew at Mountain Stihl in Helena, MT.
Date published: 2018-02-28
Rated 1 out of 5 by from Blown motor Bought saw in December, it's only been fueled with pure mix stihl gas already mixed. Had made 6 stump cuts, and maybe 8 other big cuts, started dogging them completely lost power. Took to dealer, they talked to stihl said jugs and piston bad needed rebuilt. Not warrantied..... How is that even possible. I have 12 year old saws that still run good , I keep very good care of my saws sand their operations. Totally switching after 20 years to husky
Date published: 2018-02-19
Rated 5 out of 5 by from The best saw I have owned! Some people complain a little on the weight of this saw but I don't have a problem with it and with a properly sharpened chain the weight of the saw does all the work. After I broke in the saw I used it to buck up a fir log that was 36 inches on the butt. The saw went through it like butter!
Date published: 2018-02-19
Rated 5 out of 5 by from Excellent The 391 Farm Boss head then more than reliable and dependable has plenty of power. I have a 25 inch bar on mine which is Max I believe but it's all the saw that I need and I tackle the task of trees that are 40 plus in diameter I would never go with another brand again which have always proving to be unreliable and pieces of ....!!!!
Date published: 2018-02-15
Rated 5 out of 5 by from Runs hard and cuts even even harder. Very pleased. Dads 038 mag was a heck of a saw. I loved that thing. Long sad story short she is still running but not on our farm. Picked this haus. Fired it up on 3 pulls (the way stihl should) had a BIG hickory down and my farm boss was too small. This hog ate that tree. So proud of my new saw and welcome it proudly to the stihl family in the barn. Thank you stihl for making a quality that I can count on.
Date published: 2018-02-11
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