STIHL MS 391 Chainsaw – 20" & 25" Bar Options

The STIHL MS 391 Chainsaw is a powerful all-purpose gas chainsaw built for demanding cutting jobs around the farm, ranch, property, and jobsite. With 4.4 bhp of engine power, approximately 64.1 cc (3.9 cu. in.) displacement, and a strong power-to-weight ratio, the MS 391 is designed for felling trees, cutting firewood, storm cleanup, timber work, and other heavy cutting applications.

This listing offers the STIHL MS 391 with your choice of a 20-inch or 25-inch guide bar configuration. Select the bar-length option you want before adding the saw to your cart.

California Notice: This product is not available for purchase or delivery in California.

STIHL MS 391 20" & 25" Chainsaw Options

Rather than maintaining separate pages for each common bar configuration, this MS 391 listing allows you to select the bar length that best suits your cutting needs.

Select the desired bar-length variant on this product page before ordering.

STIHL MS 391 Specifications

Actual cutting length is shorter than the nominal guide-bar length. Exact bar, chain and system-weight specifications vary with the selected configuration.

Built for Big Cutting Jobs

The STIHL MS 391 is designed for users who need more cutting power than a light-duty homeowner saw but still want a practical all-purpose machine for property, farm, ranch, and construction work.

Typical MS 391 applications include:

• Felling trees
• Cutting firewood
• Bucking logs
• Storm cleanup
• Farm and ranch maintenance
• Timber and construction work
• Large-property maintenance

The MS 391 produces more power than the MS 311 while maintaining a similar powerhead weight, making it a strong option when additional cutting performance is needed without a major increase in saw weight.

20-Inch STIHL MS 391

The 20-inch MS 391 configuration offers a versatile setup for firewood, property cleanup, felling, and general-purpose cutting.

For customers who regularly move between different types of cutting jobs, the 20-inch configuration provides a practical balance of cutting capacity and maneuverability.

25-Inch STIHL MS 391

The 25-inch STIHL MS 391 option provides additional bar length for larger cutting applications.

If you are specifically looking for a STIHL MS 391 25-inch chainsaw, select the 25-inch configuration from the available variants on this listing.

IntelliCarb™ Compensating Carburetor

The STIHL IntelliCarb™ Compensating Carburetor is designed to help maintain the correct air-to-fuel ratio as the air filter becomes restricted during use.

The system uses pressure information from the clean side of the air filter to compensate for reduced airflow, helping the engine maintain proper operating characteristics as the filter accumulates dirt.

Pre-Separation Air Filtration

The MS 391 uses a pre-separation air filtration system that removes heavier debris from incoming air before that air reaches the main filter.

This reduces the amount of dirt reaching the air filter and can extend the interval between filter cleanings compared with a conventional filtration design.

STIHL Anti-Vibration System

STIHL's anti-vibration system helps reduce the amount of engine and cutting-system vibration transferred to the operator.

That becomes especially useful during longer firewood, property-maintenance, and storm-cleanup jobs.

Side-Access Chain Tensioner

The side-access chain tensioner places the adjustment point in a convenient location on the side of the saw, making chain-tension adjustments easier with the appropriate bar wrench.

Toolless Fuel & Oil Caps

The MS 391 uses toolless fuel and chain-oil caps with retainers. Lift the lever and turn the cap to open or close it without requiring a separate tool.

Master Control Lever™

The Master Control Lever™ combines several operating functions into a single control, including choke, starting throttle, and engine on/off functions.

Bumper Spikes

Integrated bumper spikes help provide leverage and control while cutting, particularly when making larger cuts where maintaining consistent positioning against the wood is important.

STIHL MS 391 Price & Availability

If you are comparing the STIHL MS 391 price or looking for a STIHL MS 391 for sale, use the price and availability shown directly on this product page.

Because this listing offers both 20-inch and 25-inch configurations, pricing may differ depending on the selected bar-length variant.

STIHL MS 391 Instruction Manual

For operating, starting, maintenance, safety, and service information, see the official manual:

STIHL MS 311 / MS 391 Instruction Manual

Extend Eligible Warranty Coverage

For eligible STIHL gasoline-powered equipment purchased for personal, non-income-producing household use, STIHL offers extended limited-warranty coverage when qualifying STIHL fuel or oil products are purchased with the equipment.

One qualifying option is a six-pack of STIHL HP Ultra Oil. Eligibility and restrictions apply; review the applicable STIHL warranty terms for complete details.

View STIHL Warranty and Shipping Policy

Frequently Asked Questions

What size engine does the STIHL MS 391 have?

The STIHL MS 391 has approximately 64.1 cc / 3.9 cu. in. of displacement and is rated at 4.4 bhp.

How much does the STIHL MS 391 weigh?

The MS 391 powerhead weighs approximately 13.8 lb. without fuel, guide bar, or saw chain. Total system weight varies with the selected bar and chain configuration.

What bar sizes are available on this STIHL MS 391 listing?

This listing offers both 20-inch and 25-inch guide-bar configurations. Choose the desired option before adding the saw to your cart.

Can I buy a STIHL MS 391 with a 25-inch bar?

Yes. A 25-inch MS 391 configuration is available as a selectable variant on this listing.

Can I buy the MS 391 with a 20-inch bar?

Yes. This listing also offers a 20-inch STIHL MS 391 configuration.

What chain pitch does the STIHL MS 391 use?

The STIHL MS 391 uses a 3/8-inch saw-chain pitch. Confirm the exact bar and chain specification for the selected variant when replacing cutting components.

What is the STIHL MS 391 used for?

The MS 391 is designed for demanding all-purpose cutting, including felling trees, cutting firewood, farm and ranch work, construction, and storm cleanup.

Is the STIHL MS 391 more powerful than the MS 311?

Yes. STIHL describes the MS 391 as more powerful than the MS 311 while remaining similar in powerhead weight.

Does the STIHL MS 391 have M-Tronic?

The specifications supplied for the MS 391 identify an IntelliCarb™ Compensating Carburetor, not an M-Tronic electronic engine-management system.

How do I start a STIHL MS 391?

Follow the starting procedure in the official STIHL MS 311 / MS 391 instruction manual linked above. The MS 391 uses a Master Control Lever™ that combines starting and operating functions.

How much is a STIHL MS 391?

Check the current price shown on this product page. Pricing can vary between the 20-inch and 25-inch bar configurations.

Can the STIHL MS 391 be purchased or delivered in California?

No. This listing is not available for purchase or delivery in California.

STIHL MS 391 Chainsaw for Sale

Choose the STIHL MS 391 when you need a powerful gas chainsaw for firewood, felling, farm and ranch work, construction, or demanding property cleanup. Select either the 20-inch or 25-inch bar configuration available on this page to match the saw to your cutting needs.