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

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.

    More information

  • 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.
  • 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.


45.6 cc (2.78 cu. in.)
2.2 kW (2.95 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 depending upon which powerhead it is installed.

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 4.4 out of 5 by 200.
Rated 5 out of 5 by from Super reliable! Starts every time, really fun and easy to use, but most important, its very reliable.
Date published: 2017-03-25
Rated 5 out of 5 by from A product with excellent reliability. When I realized I needed to purchase a new chain saw the first name that came to mind was Stihl. The reason for thinking Stihl is reliability. I learned this years ago by purchasing other Stihl products. Reliability comes from quality and giving the customer a great machine and standing behind it. In the event repair is ever needed the expertise of highly trained technicians to restore the machine to top performance is available locally.
Date published: 2017-03-23
Rated 4 out of 5 by from Reliable saw I am the head fleet mechanic for a landscape company and deal with a ton of small equipment. I have always felt that the Stihl products were superior to others. This is not my first Stihl saw, I had an ms310 that gave up the fight after hundreds of cords of wood. Wanted a lighter saw that could still handle an 18" bar. It doesn't hog as fast as the 310 through a tree but my back thanks it. It's significantly better on fuel. Only problem I had with it is as when it was new, seemed to flood easy. 3 pulls on any Stihl I have been around usually floods it but this one was extra sensitive. I switched to using the premixed fuel at the John Deere dealer in town and haven't had a problem since. I chocked it up to ethanol in the fuel at the local gas stations and the higher price is worth it to mean in longevity of the machine and less frustration. Other than that, it's a great saw for use cutting wood for th burner and building fences for the cows. Happy to stand behind it.
Date published: 2017-03-20
Rated 5 out of 5 by from Outstanding performance It is an awesome product, very dependable. Never fails to start. I would highly recommend this saw in fact I have.
Date published: 2017-03-19
Rated 5 out of 5 by from Awesome product What a great product easy to start and maintain and very reliable
Date published: 2017-03-15
Rated 5 out of 5 by from This product has great features and power I have only used the saw to trim several 3'' to 4'' branches ,but it starts easy and is very easy to handle. It has more than enough power to do the jobs i need to do around the house and at my deer lease.
Date published: 2017-03-14
Rated 5 out of 5 by from best chainsaw I have used My wife and I are clearing 2 acres wih only this saw and our hands, and I couldn't be happier with it. Starts easy cuts through the trees with ease. I can't believe the difference it makes when you buy a quality product instead of the other 2 we have bought. Highly recommend this chainsaw.
Date published: 2017-03-13
Rated 5 out of 5 by from Great saw, light weight Great saw - well balanced with the 18 inch blade, easy to grip and use, light weight, good power to weight ratio, 3/8 chain makes quick, clean cuts.
Date published: 2017-03-08
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Standard Features

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

You Will Also Need

For Your Safety


Read what our customers say about STIHL chainsaws 
Chainsaw Safety and Maintenance - Video
Product Instruction Manual (PDF)
Product Safety Manual (PDF)
STIHL Limited Warranty
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