STIHL MS 661 Petrol Chainsaw
Price range: £1,394.58 through £1,417.33
Product information & specifications
STIHL MS 661 Petrol Chainsaw Review
This review takes a close look at the STIHL MS 661 Petrol Chainsaw and what makes it a standout professional cutting tool. You’ll find an overview of who it suits best, the key technologies that drive its performance, a concise specifications list, a neutral comparison with similar high-end saws, practical usage tips, and clear answers to the most-searched questions buyers ask.
Who the STIHL MS 661 Petrol Chainsaw is for
The MS 661 is ideal for users who want uncompromising performance for large-diameter timber, felling, and heavy-duty bucking. Professional forestry teams, sawyers processing big logs, and experienced landowners working with dense hardwoods will appreciate its sustained torque, fast acceleration, and durable construction. It’s also an excellent fit for operators who value intelligent engine management, reduced maintenance intervals, and comfort-enhancing features that support long workdays with confidence.
Key features
M-Tronic electronic engine management delivers a consistently strong cut from the first trigger pull. The system automatically regulates ignition timing and fuel metering, continuously adapting to temperature, altitude, and fuel quality. The result is optimal engine performance, responsive acceleration, and dependable power delivery in changing conditions.
High-efficiency 2-MIX engine combines impressive power output with fuel-savvy operation. It’s engineered to reduce exhaust emissions and fuel consumption while maintaining high power levels, and it complies with strict EU Stage V emissions standards.
Controlled-delivery oil pump with E position tailors lubrication to the job. Select the E setting to reduce chain oil consumption by up to 50%, or quickly increase flow for longer guide bars or very dry wood. Paired with the Ematic lubrication system, which directs oil precisely where it’s needed, this setup promotes smooth cutting and efficient oil use.
HD2 long-life air filter safeguards the engine against fine dust. Made from PET material with very fine pores, it’s oil- and water-repellent for easier cleaning and extended service life. The cartridge can be replaced without tools, supporting quick turnaround between jobs.
Compensator carburettor control helps keep engine performance, exhaust quality, and fuel use virtually constant over long periods, even as the air filter accumulates debris. This means fewer interruptions and more time cutting.
Comfort and control enhancements include an anti-vibration system that reduces transmission of vibrations to the handles, promoting a more relaxed grip and less fatigue. A decompression valve lightens pull-start effort, while a single start position on the combi lever with an automatic stop function returns the control to the operating position for fast warm restarts.
Professional usability details speed up daily workflows: side-mounted chain tensioning keeps hands clear and makes re-tensioning quick; captive nuts on the sprocket cover prevent loss during chain swaps; and tool-free fuel and oil caps open and close securely in seconds. Guide bar exterior designs can change over time, while technical performance remains consistent. For replacements, a dedicated bar and chain advisor helps you match the correct cutting attachments to this saw.
STIHL MS 661 Petrol Chainsaw specifications
- Displacement: 91.
1 cm³ - Power: 5.
40 kW - Engine power: 7.
30 HP - CO2: 679 g/kWh
- Device weight without refuelling: 7.
5 kg - System weight without refuelling: 9.
22 / 10.
38 kg - Power-to-weight ratio: 1.
40 kg/kW - Bar length: 71 / 90 cm
- Bar length: 28 / 36 in
- Groove width: 1.
60 mm - Saw chain pitch: 3/8″
- Device length with bumper spike: 467 mm
- Sound pressure level: 105 dB(A)
- Sound power level: 115 dB(A)
- Vibration level, left: 6.
9 m/s² - Vibration level, right: 5.
6 m/s²
STIHL MS 661 Petrol Chainsaw vs similar models
Compared with a lighter professional saw focused on extreme maneuverability and fast pick-up, the MS 661 leans into maximum torque and long-bar compatibility. This benefits users working in big timber who want confident, continuous cutting pressure and the ability to run extended guide bars with strong oiling support.
Against ultra-high-displacement flagship models designed for the very largest trees, the MS 661 offers a balanced blend of power and manageability. It maintains pro-grade cutting speed and bar length options while staying highly controllable for felling, bucking, and high-output ground work day after day.
Across the spectrum of premium petrol chainsaws, the MS 661 stands out for its integration of M-Tronic engine management, efficient 2-MIX technology, advanced filtration, and a lubrication system that can be tuned precisely to the wood and bar length in use.
Usage tips
- Choose a bar length that matches your wood diameter and cutting style; the saw accommodates long bars for big timber while retaining excellent torque.
- Set the oil pump to the E position for general cutting to reduce consumption; increase oil flow when using very long bars or working in dry, dusty conditions.
- Use the side-mounted tensioner for quick, protected chain adjustments. Re-tension after the first few cuts on a new chain and periodically during long sessions.
- Keep the HD2 filter clean to sustain peak performance; its oil- and water-repellent surface makes maintenance straightforward, and the cartridge swaps without tools.
- Take advantage of the decompression valve for easy starts and the combi lever’s stop function for fast warm restarts between cuts.
- Pair the correct 3/8″ chain and 1.
60 mm groove width guide bar. A bar and chain advisor is helpful for confirming exact compatibility. - Maintain a sharp chain, proper chain brake function, and a firm, balanced stance. The anti-vibration system supports comfort—let the saw do the work.
- Fuel with a quality petrol and 2-stroke oil mix as recommended for 2-MIX engines to uphold clean running and strong acceleration.
Frequently asked questions
What is the displacement of the STIHL MS 661?
The MS 661 has a displacement of 91.
1 cm³, delivering high torque and robust cutting performance for big timber work.
How much does the STIHL MS 661 weigh?
The device weight without refuelling is 7.
5 kg. System weight without refuelling is listed at 9.
22 / 10.
38 kg, depending on the cutting setup.
What bar length does the STIHL MS 661 use?
It supports bar lengths of 71 cm or 90 cm (28 in or 36 in), giving you flexibility for felling and bucking large-diameter wood.
Does the STIHL MS 661 have M-Tronic?
Yes. M-Tronic electronically manages ignition timing and fuel metering, adapting to temperature, altitude, and fuel quality for optimal performance.
What chain pitch is on the STIHL MS 661?
The saw uses a 3/8″ chain pitch. Match it with a compatible bar and chain set for best results.
What is the power output of the STIHL MS 661?
The engine produces 5.
40 kW, equivalent to 7.
30 horsepower, supporting fast acceleration and sustained cutting force.
How loud is the STIHL MS 661?
The sound pressure level is 105 dB(A) and the sound power level is 115 dB(A). Use appropriate hearing protection during operation.
What are the STIHL MS 661 vibration levels?
Vibration at the handles is rated at 6.
9 m/s² on the left and 5.
6 m/s² on the right, complemented by an anti-vibration system for comfortable handling.
| Displacement | 91.1 cm³ |
| Power | 5.40 kW |
| Engine power | 7.30 HP |
| CO2 | 679 g/kWh |
| Device weight without refuelling | 7.5 kg 1) |
| System weight without refuelling | 9.22 / 10.38 kg 2) |
| Power-to-weight ratio | 1.40 kg/kW |
| Bar length | 71 / 90 cm 3) |
| Bar length | 28 / 36 in 3) |
| Groove width | 1.60 mm |
| Groove width | 63 in |
| Saw chain pitch | 3/8" |
| Device length with bumper spike | 467 mm 1) |
| Sound pressure level | 105 dB(A) 4) |
| Sound power level | 115 dB(A) 4) |
| Vibration level, left | 6.9 m/s² 5) |
| Vibration level, right | 5.6 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.
With STIHL M-Tronic, you’ll have the best performance from your work tool from the outset. Fully electronic engine management regulates the ignition timing and fuel metering in all work situations, taking into account external conditions such as temperature, altitude and fuel quality.
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 HD2 filter protects your power tool’s engine against even the finest dust, ensuring a longer service life and reduced wear. The filter made from PET material has up to 70% finer pores than fleece and polyamide filters, and is also oil- and water-repellent. This also makes it easier to clean the filter. When needed, the filter cartridge can be easily replaced without tools.
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.
This makes it impossible for the nuts to fall off and get lost when the cover is removed.
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.
Only one start position is required on the combi lever. Thanks to the stop function, once the machine is turned off the control lever immediately moves back into the operating position. This allows a warm machine to be restarted immediately.
With the STIHL 2-MIX engine, you can reduce exhaust emissions and fuel consumption, and therefore operating costs. This 2-stroke engine is low-maintenance and uses fuel efficiently even at high power levels. Use a mixture of petrol and engine oil as fuel. The STIHL 2-MIX engine complies with the strict EU Stage V emissions directive.
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