STIHL MS 391 Petrol Chainsaw
Price range: £765.16 through £772.74
Product information & specifications
STIHL MS 391 Petrol Chainsaw Review
This review explores the STIHL MS 391 Petrol Chainsaw in depth, focusing on real-world performance, user comfort, and efficiency. You’ll find who it suits best, standout features, full specifications, a comparison with closely related models, practical usage tips, and clear answers to frequently asked questions. The goal is to help you choose with confidence and get the most from this high‑torque, easy‑to‑manage chainsaw.
Who the STIHL MS 391 Petrol Chainsaw is for
The STIHL MS 391 is ideal for landowners, smallholders, and property managers who want confident cutting power with refined handling. It excels when processing firewood, harvesting timber, and managing stormfall, offering strong torque across a wide speed range for smooth cutting through dense hardwoods and large logs. It’s also a smart fit for farmers and estate teams who appreciate reduced maintenance intervals and purposeful features that simplify day‑to‑day tasks. With its comfortable ergonomics, fuel‑saving engine design, and user‑friendly controls, the MS 391 supports productive work sessions and dependable results.
Key features
High torque across wide RPMs
The MS 391 delivers strong pulling power over a broad speed band, supporting confident cuts in larger timber and sustained performance when bucking firewood.
Efficient 2‑MIX engine
The engine technology is designed for excellent output with smart fuel use, achieving up to 20% less fuel consumption and up to 50% lower emissions compared with the previous model without 2‑MIX technology.
Four‑channel technology for responsive power
Optimized fuel‑air flow enhances combustion efficiency, promoting high performance with impressively low fuel usage.
Side‑mounted chain tensioning
A protected, lateral tensioning screw enables quick, simple chain adjustments and straightforward chain changes, helping you stay productive between cuts.
Controlled‑delivery oil pump
Select the E position to reduce bar and chain oil consumption by up to 50%. When working in very dry conditions or with long cutting attachments, you can easily increase oil flow for added protection.
STIHL Ematic lubrication system
The Ematic system directs oil precisely where it’s needed, improving lubrication and enabling up to 50% less oil use. Oil flow can be boosted rapidly when conditions demand it.
Compensator for consistent performance
A smart carburettor control helps maintain engine output and fuel mix quality as the air filter loads with dust, extending working intervals between filter cleanings.
Decompression valve for easier starts
By releasing some cylinder pressure during start‑up, the decompression valve lowers pull force on the starter cord and protects the starting system.
Anti‑vibration comfort
Buffer and spring elements isolate vibrations from the handle area, making the saw more pleasant to hold and helping reduce user fatigue during longer tasks.
Tool‑free fuel and oil caps
Bayonet closures let you open and close tanks quickly without tools, streamlining refuelling and top‑ups.
STIHL MS 391 Petrol Chainsaw specifications
- Displacement: 64.
1 cm³ - Power: 3.
30 kW - Engine power: 4.
50 HP - CO2: 653 g/kWh
- Device weight without refuelling: 6.
3 kg - System weight without refuelling: 7.
43 / 7.
55 kg - Power‑to‑weight ratio: 1.
90 kg/kW - Bar length: 45 / 50 cm (18 / 20 in)
- Saw chain pitch: 3/8″
- Groove width: 1.
60 mm - Device length with bumper spike: 458 mm
- Sound pressure level: 105 dB(A)
- Sound power level: 115 dB(A)
- Vibration level, left: 4 m/s²
- Vibration level, right: 4 m/s²
STIHL MS 391 Petrol Chainsaw vs similar models
The MS 391 serves as a powerful, comfort‑oriented chainsaw that blends high torque with user‑friendly operation. Compared with a smaller farm‑class model such as the STIHL MS 311, the MS 391 emphasizes broader torque delivery and supports popular 45–50 cm (18–20 in) bar lengths for confident cutting in larger rounds. For users considering a more professional‑leaning option like the STIHL MS 362, the MS 391 offers an attractive balance of performance and approachable handling, with efficiency‑focused engine technologies and practical features such as side‑mounted chain tensioning and tool‑free caps. In both directions, the choice comes down to the mix of power, ergonomics, and duty cycle you value most—MS 391 stands out for strong torque, refined lubrication control, and long, low‑maintenance working intervals.
Usage tips
- Use the side‑mounted chain tensioner to set correct chain tension before each session; a properly tensioned chain improves cutting accuracy and extends bar and chain life.
- Set the oil pump to the E position for typical conditions, then increase oil flow when working with longer bars or in very dry wood to maintain ideal lubrication.
- Make the most of the Ematic system by pairing quality bar and chain oil with a sharp, correctly filed chain for smooth, efficient cuts.
- Engage the decompression valve during cold starts to reduce pull effort and protect the starter mechanism.
- Monitor performance; when you notice a drop, clean the air filter. The compensator helps keep output steady for long stretches between cleanings.
- Choose the recommended bar length for the task at hand—18 in for agile firewood work and 20 in for larger timber—guided by the saw’s capabilities.
- Refuel and top up oil with the tool‑free bayonet caps on stable ground, wiping debris from caps and filler necks to keep contaminants out.
- Use well‑fitting PPE and maintain a sharp chain to maximize the benefits of the anti‑vibration system and reduce user fatigue.
Frequently asked questions
What is the power output of the STIHL MS 391?
The STIHL MS 391 produces 3.
30 kW of power, equivalent to 4.
50 HP, delivering strong torque for confident cutting in firewood processing and timber work.
How much does the STIHL MS 391 weigh?
The device weight without refuelling is 6.
3 kg. System weight without refuelling is listed at 7.
43 / 7.
55 kg.
What bar length does the STIHL MS 391 use?
It supports bar lengths of 45 cm and 50 cm, which correspond to 18 in and 20 in, making it versatile for both firewood and larger logs.
Does the STIHL MS 391 have a decompression valve?
Yes. The decompression valve eases starting by releasing some cylinder pressure, reducing the force needed on the starter cord.
How do you adjust the chain tension on a STIHL MS 391?
Use the side‑mounted chain tensioner. Insert the tool laterally through the sprocket cover and turn the tensioning screw to achieve proper chain tension.
Is the STIHL MS 391 fuel efficient?
Yes. Its 2‑MIX and four‑channel technologies are designed for efficient combustion, with up to 20% less fuel consumption versus the previous non‑2‑MIX model.
| Displacement | 64.1 cm³ |
| Power | 3.30 kW |
| Engine power | 4.50 HP |
| CO2 | 653 g/kWh |
| Device weight without refuelling | 6.3 kg 1) |
| System weight without refuelling | 7.43 / 7.55 kg 2) |
| Power-to-weight ratio | 1.90 kg/kW |
| Bar length | 45 / 50 cm 3) |
| Bar length | 18 / 20 in 3) |
| Groove width | 1.60 mm |
| Groove width | 63 in |
| Saw chain pitch | 3/8" |
| Device length with bumper spike | 458 mm 1) |
| Sound pressure level | 105 dB(A) 4) |
| Sound power level | 115 dB(A) 4) |
| Vibration level, left | 4 m/s² 5) |
| Vibration level, right | 4 m/s² 5) |
Product Info
Product Info
Side-mounted chain tensioning allows for protected, easy and quick chain tensioning and replacement. The tensioning screw is inserted laterally through the sprocket cover.
The controlled-delivery oil pump reduces your chainsaw’s oil consumption by up to 50%. To use it, simply select the E position. For very long cutting attachments or very dry wood, an additional oil volume can be set by the user.
The compensator is a control system in the carburettor, which uses pressure compensation to ensure that engine performance, exhaust gas quality and fuel consumption remain virtually constant over a long period of time, despite increasing contamination of the air filter. You do not need to clean the air filter until there is a noticeable drop in performance. This means that you can work for a long time without maintenance.
With tool-free fuel cap, you can open and close oil and fuel tanks in just a few simple steps, thanks to a bayonet closure.
The STIHL Ematic system comprises a STIHL Ematic or Ematic S guide bar, a STIHL Oilomatic saw chain and a controlled-delivery oil pump. It ensures that the chain oil gets to where it is needed for lubrication. This allows you to reduce oil consumption by up to 50%. If you often work in dusty conditions or if you use long guide bars, you can quickly and easily increase the oil quantity at any time with the new oil pump system.
Thanks to STIHL four-channel technology, you can work with your power tool with very low fuel consumption and high performance. The four overflow channels guide the fuel-and-air mixture into the cylinder in a targeted and more compressed manner, which optimally burns the fuel and significantly increases the performance of the engine.
The decompression valve makes it easier to start your power tool. When starting, you can allow some of the compressed mixture to escape from the cylinder by opening the valve. This protects the start-up system and reduces the amount of force required on the starter cord.
Vibrations can occur when you put your power tools through their paces, and these are particularly noticeable in the grip area. The buffer and spring elements of the STIHL anti-vibration system reduce the transmission of vibrations to the handle area and therefore to your body. The result is that your power tool is more comfortable to hold and your work is much less tiring.
Warranty & Manuals
Warranty
STIHL offer a 1 year professional warranty or 2 year domestic warranty with all of their machines.
The following exceptions apply:
- AK System, AS System and AI Line cordless products aren't covered under warranty when used by professionals
- AP System machines, batteries and chargers - 2 year professional warranty
- Pressure washers - 2 year professional warranty or 3 year domestic warranty
- Mowers, tillers, shredders, scarifiers & iMOW machines
Extend your Stihl warranty by an additional year when purchasing a STIHL Smart Connector with selected machinery from the petrol and cordless range. Extends your petrol warranty from 1 to 2 years AND 2 to 3 years on select cordless tools.
Delivery & Returns
Delivery
UK Standard Delivery from - £11.00
Estimated delivery 2-4 days
Free Delivery available for orders above £150 Inc VAT
Estimated delivery 2-4 days
Returns
Returns
30-Day Return Policy
Faulty returns please call us on 01603 754890
For more information on shipping options, visit our contact us page