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A powerful and fuel-efficient chainsaw that’s comfortable to use.

Product Description

The STIHL MS 251 WOOD BOSS® Chainsaw is designed to deliver all the power you’d expect from STIHL equipment, yet with a comfortable and ergonomic design. The MS 251 WOOD BOSS® is perfect for felling small trees, pruning and thinning, and cutting firewood simply and efficiently. And with up to 20 percent fuel savings and 50 percent reduced emissions (as compared to previous models), you can enjoy a longer run time while feeling good about your impact on the environment. Features like a Master Control Lever™ and reduced vibration make the STIHL MS 251 WOOD BOSS® a lean, easy-to-use machine that still packs plenty of power.

Model Features

  • 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.

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  • Built in the USA
    Indicates products that are built in the United States from domestic and foreign parts and components.

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  • Master Control Lever™
    The Master Control Lever™ is an easy to use single lever, operating the choke, starting throttle lock and on-off switch. The operator must pull the throttle trigger before moving the Master Control Lever™ to the choke position.


45.6 cc (2.78 cu. in.)
2.2 kW (3.0 bhp)
4.9 kg (10.8 lbs.)
390 cc (13.2 oz.)
198 cc (6.7 oz.)
.325" RM3
GUIDE BAR LENGTHS (Recommended ranges)
40 to 45 cm (16" to 18")
STIHL recommends #3634 (26 RM3 68) OILOMATIC® saw chain and 18" 3005 008 4717 STIHL ROLLOMATIC® E guide bar combination. The actual listed guide bar length can vary from the effective cutting length based on which powerhead it is installed on.

Important Information

* The actual listed guide bar length can vary from the effective cutting length based on which powerhead it is installed on.

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.


MS 251 WOOD BOSS® is rated 4.3 out of 5 by 442.
Rated 4 out of 5 by from MS 251 Wood Boss Review The MS 251 Wood Boss is a good saw, but I finding it lacking (power) compared to the MS 250 that it replaced. Other than that the two saws are virtually identical. To me a chainsaw needs that straight (when called upon) power like that of the MS 250, but with the MS 251 one has to get it spooled up before making the cut, and that's not a good look for a quality saw. It is for this reason that I could only give the MS 251 Wood Boos four out of five starts. It's still a quality STIHL product, but every time I use it I miss my old MS 250.
Date published: 2019-07-15
Rated 5 out of 5 by from Great home use saw I love this saw I have 11 acres and this makes my job easier good power for money 18 in bad was plenty for me typically use couple times a month at least
Date published: 2019-07-10
Rated 5 out of 5 by from STIHL - best products out there. I've had plenty of other brand saws over the years and only a couple of those lasted several years of hard use. But even then they dint come close to a STIHL. I've had an STIHL SF 55 weed eater since1986 and it still runs great, even with little maintenance. I love the size, power, simplicity and the dependability of the my new 251 Wood Boss. I am very pleased with my purchase and hope to get many years of service from this trusted brand.
Date published: 2019-07-08
Rated 5 out of 5 by from Awesome product This saw is so lightweight and powerful, it handles the 18 inch bar well and it has been through it all and it will still start right back up after 3 years of service so far.
Date published: 2019-07-07
Rated 3 out of 5 by from This saw failed twice this year when I needed it the most. I like the saw for its power, weight and engineering. That said, it has been back to the dealer twice this past year for not oiling the chain. The first time was during hurricane cleanup in North Carolina. Yesterday it stopped oiling while cutting a hickory tree in my yard that was blown over in a storm. And yes, it had chain oil in it. I’m disappointed that I can’t trust this saw. I spent a long time researching the right saw for my needs and In the end, I went with stihl for the dealer network and reputation. I own several stihl products and have been happy with them.
Date published: 2019-06-24
Rated 5 out of 5 by from So far it has been great. Does everything I expected. I bought my saw at Westlake ACE hardware and got a good deal on it. I feel like it does a great job. It goes through wood like a knife through butter. So far I have loved it. It starts very easy and keeps running through everything I have cut so far.
Date published: 2019-06-18
Rated 4 out of 5 by from NIce Saw Nice saw all around but starting is the only fault I have with saw. It is hard to start but I may get better at starting it as time goes on. I hope so.
Date published: 2019-06-17
Rated 5 out of 5 by from great value Starts quickly and doesn’t stop working hard. Cuts well
Date published: 2019-06-10
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Standard Features

  • Common Features for Chainsaws
    View the features common to many STIHL chainsaws.

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