Stihl MS261 C-M Chainsaw

Description

Lightweight professional forestry chainsaw with M-Tronic

The STIHL MS 261 C-M is a professional 50.2 cm³ petrol chainsaw designed for forestry, arboriculture, tree maintenance and intensive timber processing.

Its STIHL 2-MIX engine produces 3.0 kW / 4.1 hp from a powerhead weighing approximately 4.9 kg without fuel, guide bar or saw chain. This combination gives the MS 261 C-M an excellent power-to-weight ratio for felling, snedding, thinning and processing small-to-medium timber.

STIHL M-Tronic electronic engine management automatically controls ignition timing and fuel metering, allowing the chainsaw to adapt to changes in temperature, altitude, fuel quality and operating conditions without normal manual carburettor adjustment.

The current machine is supplied with a lightweight STIHL Light 04 guide bar and a narrow-kerf .325″ Rapid Super Pro chain for fast professional cutting performance.

Every petrol chainsaw sold by Masseys is assembled, inspected, test-run and registered by our trained team before handover.

Browse our complete range of STIHL petrol chainsaws, read the Masseys STIHL chainsaw buying guide or use our STIHL chainsaw comparison chart.

Key features of the STIHL MS 261 C-M

• Professional forestry petrol chainsaw
• 50.2 cm³ STIHL 2-MIX engine
• 3.0 kW / 4.1 hp power output
• 4.9 kg powerhead weight without fuel, bar or chain
• Approximately 1.6 kg/kW power-to-weight ratio
• STIHL M-Tronic electronic engine management
• Choice of 16″ / 40 cm or 18″ / 45 cm guide bar
• Lightweight STIHL Light 04 guide bar
• .325″ Rapid Super Pro full-chisel saw chain
• 1.3 mm chain gauge
• Adjustable chain-oil delivery
• Side-mounted chain tensioning
• Captive sprocket-cover nuts
• Easy-clean HD2 air filter
• Stainless-steel muffler
• STIHL anti-vibration system
• Tool-free fuel and chain-oil caps
• Decompression valve for easier starting

Who should choose the STIHL MS 261 C-M?

The MS 261 C-M is intended for professional and highly experienced users who need strong cutting performance without carrying the additional weight of a larger-displacement forestry saw.

Typical applications include:

• Professional forestry work
• Felling appropriately sized small and medium trees
• Snedding and branch removal
• Thinning woodland
• Cross-cutting timber
• Commercial firewood preparation
• Estate and woodland management
• Arboricultural ground work
• Storm-clearance operations

The MS 261 C-M is likely to be unnecessarily specialised for occasional garden pruning or small quantities of domestic firewood.

Choosing a 16-inch or 18-inch guide bar

Masseys offers the MS 261 C-M with a 16″ / 40 cm or 18″ / 45 cm STIHL Light 04 guide bar.

Both versions use the same 50.2 cm³ powerhead and produce the same 3.0 kW / 4.1 hp output. The guide-bar length changes the saw’s reach, chain length, front-end weight and handling—not its engine power.

16″ / 40 cm Light 04 guide bar

The 16-inch configuration is the balanced choice for much professional forestry and woodland work.

Choose it when:

• Snedding and manoeuvrability are priorities
• You regularly work around closely spaced trees or branches
• The majority of timber does not require an 18-inch bar
• You want the lightest and most agile Masseys configuration

18″ / 45 cm Light 04 guide bar

The 18-inch configuration provides additional reach for larger stems and cross-cutting work.

Choose it when:

• You regularly encounter larger-diameter timber
• The additional guide-bar reach is genuinely useful
• You are comfortable with the extra leverage at the front of the saw

For most mixed forestry work, select the shortest guide bar that comfortably suits the timber being cut.

STIHL M-Tronic engine management

STIHL M-Tronic is a fully electronic engine-management system.

It automatically regulates:

• Ignition timing
• Fuel metering
• Starting settings
• Engine response across the operating range

The system accounts for factors including:

• Engine temperature
• Ambient temperature
• Altitude
• Fuel quality
• Air-filter condition
• Changing operating loads

M-Tronic removes the need for normal manual carburettor adjustment and helps maintain strong acceleration and consistent cutting performance as working conditions change.

The system also stores recent operating settings. When the working conditions remain similar, those settings are applied when the chainsaw is restarted.

Simplified M-Tronic starting

An M-Tronic chainsaw uses one cold-start position rather than separate full-choke and half-choke positions.

After the engine starts, pressing the throttle allows the control lever to return to the normal operating position.

The decompression valve reduces cylinder pressure during starting, helping lower the force required on the starter cord.

Always follow the starting procedure in the MS 261 C-M operating manual because reset and calibration procedures can differ between M-Tronic generations.

50.2 cm³ STIHL 2-MIX engine

The 50.2 cm³ STIHL 2-MIX engine produces 3.0 kW / 4.1 hp.

STIHL 2-MIX technology is designed to provide high torque and professional cutting output while reducing fuel consumption and exhaust emissions compared with older equivalent STIHL two-stroke engines without 2-MIX technology.

The magnesium engine housing contributes to the machine’s low weight and professional durability.

Light 04 guide bar

The STIHL Light 04 guide bar uses a slim, lightweight construction designed to improve the balance and handling of professional chainsaws.

Compared with a conventional Rollomatic bar, its reduced front-end mass can make the saw easier to manoeuvre during snedding, felling and repeated forestry cuts.

The Light 04 system fitted to the MS 261 C-M uses a .325″ pitch and 1.3 mm groove width.

.325″ Rapid Super Pro chain

The current MS 261 C-M cutting attachment uses a narrow-kerf .325″ Rapid Super Pro saw chain with a 1.3 mm drive-link gauge.

RS Pro is a full-chisel professional chain designed for:

• Fast cross-cutting
• Efficient bore cutting
• Felling and snedding
• High professional cutting performance
• Low vibration

The narrower kerf gives the current system up to approximately 20% greater cutting performance than the preceding .325″ Rapid Super combination under comparable conditions.

The required chain length depends on the fitted guide bar. Check the pitch, gauge, drive-link count and markings on the guide bar before ordering from Masseys’ replacement chainsaw chain range.

Side-mounted chain tensioning

The chain-tensioning screw is accessed through the side of the sprocket cover.

This gives protected access to the adjustment point without placing the combination tool directly beside the chain’s cutting teeth.

Check chain tension:

• Before each use
• After fitting a new chain
• During longer working sessions
• Whenever the chain no longer sits correctly against the underside of the guide bar

Switch off the engine, allow hot parts to cool and wear protective gloves before handling or adjusting the chain.

Captive sprocket-cover nuts

The sprocket-cover nuts remain attached to the cover when loosened.

This reduces the risk of dropping or losing them during guide-bar removal, chain changes and cleaning in the forest or workshop.

Adjustable chain-oil delivery

The MS 261 C-M has an adjustable oil pump so lubrication can be matched more closely to the fitted guide bar, timber and working conditions.

The standard setting is suitable for normal work. Increased oil delivery may be appropriate when using a longer cutting attachment or working with particularly dry timber.

Check the chain-oil level and oil delivery before starting work. Inadequate lubrication can rapidly damage the guide bar and saw chain.

HD2 air filter

The washable HD2 filter protects the engine from fine dust and debris.

Its fine PET filter material is oil- and water-repellent, helping maintain airflow and protect internal engine components in demanding forestry conditions.

The filter must still be inspected and cleaned according to the operating instructions.

Stainless-steel muffler

The stainless-steel muffler is designed to withstand demanding professional use and changing weather conditions.

Allow the exhaust and surrounding components to cool before carrying out cleaning, servicing or transport preparation.

STIHL anti-vibration system

Spring and buffer elements reduce the amount of engine and cutting vibration transmitted to the handles.

This supports greater comfort during appropriate extended professional work. It does not eliminate vibration, so correct technique, machine maintenance and regular breaks remain important.

Fuel and chain-oil requirements

The MS 261 C-M requires two separate fluids:

• A 50:1 mixture of petrol and approved two-stroke engine oil for the engine
• Dedicated chain oil for lubricating the guide bar and chain

For self-mixed fuel, use suitable fresh petrol with approved STIHL two-stroke engine oil at the correct ratio.

STIHL MotoMix ready-mixed fuel can also be used and provides a consistent 50:1 formulation with a longer storage life than ordinary self-mixed petrol.

The cutting attachment requires separate STIHL chainsaw chain oil. Two-stroke engine oil must not be placed in the chain-oil tank.

Fuel, two-stroke engine oil, chain oil and personal protective equipment are not included.

MS 251 vs MS 261 C-M vs MS 291

Specification	STIHL MS 251	STIHL MS 261 C-M	STIHL MS 291
Product class	Top-range domestic	Professional forestry	Agricultural and landowner
Engine displacement	45.6 cm³	50.2 cm³	55.5 cm³
Power output	2.2 kW	3.0 kW	2.8 kW
Powerhead weight	4.8 kg	4.9 kg	5.6 kg
Engine management	Conventional carburettor	STIHL M-Tronic	Conventional carburettor
Best suited to	Heavy domestic firewood	Commercial forestry and tree work	Agriculture, estates and heavy firewood

Choose the STIHL MS 251 for demanding private firewood work where professional construction and M-Tronic are not required.

Choose the MS 261 C-M for professional output, lower working weight and advanced engine management.

Choose the STIHL MS 291 for agricultural and estate work where its lower purchase cost is more important than the MS 261’s professional power-to-weight ratio.

MS 261 C-M or MS 400.1 C-M?

The MS 400.1 C-M is a larger professional forestry chainsaw with substantially more engine capacity and output.

Choose the MS 261 C-M when:

• Low weight and manoeuvrability are priorities
• The main work is thinning, snedding and small-to-medium timber
• A 16-inch or 18-inch guide bar is sufficient
• You want professional performance from the 50cc class

Consider the STIHL MS 400.1 C-M when:

• You regularly work with larger timber
• Higher cutting output is required
• The workload justifies moving into the professional 60cc class

Petrol MS 261 C-M or cordless MSA 300?

The professional STIHL MSA 300 cordless chainsaw provides up to 3.0 kW of electrical output with an AP 500 S battery, putting it in a similar performance category to the MS 261 C-M.

Choose the MS 261 C-M when:

• Rapid petrol refuelling is more practical than battery rotation
• Charging facilities are limited
• Very long working days are common
• You prefer a professional petrol forestry platform

Consider the MSA 300 when:

• Low noise is important
• Direct exhaust emissions must be avoided
• You already own AP 500 S batteries and professional chargers
• Work takes place near residential or noise-sensitive areas

Technical specifications

Specification	Details
Model	STIHL MS 261 C-M
Product type	Professional forestry petrol chainsaw
Engine	STIHL 2-MIX two-stroke petrol engine
Engine management	STIHL M-Tronic
Displacement	50.2 cm³
Power output	3.0 kW / 4.1 hp
Powerhead weight	4.9 kg without fuel, guide bar or saw chain
Power-to-weight ratio	Approximately 1.6 kg/kW
Guide-bar options	40 cm / 16″ or 45 cm / 18″
Guide-bar type	STIHL Light 04
Chain pitch	.325″
Chain gauge	1.3 mm / .050″
Chain type	STIHL Rapid Super Pro
Chain tensioning	Side mounted and adjusted with combination tool
Air filtration	Easy-clean HD2 filter
Chain lubrication	Automatic with adjustable oil delivery
Fuel-tank capacity	Approximately 0.50 litres
Chain-oil capacity	Approximately 0.27 litres
Fuel mixture	50:1 petrol and approved two-stroke engine oil, or STIHL MotoMix
Sound-pressure level	Approximately 105 dB(A)
Sound-power level	Approximately 114 dB(A)
Vibration level, left/right	Approximately 3.5 / 3.5 m/s²
16″ configuration MPN	11412000647 – verify against physical stock
18″ configuration MPN	11412000652 – verify against physical stock

What is included?

The standard package should include:

• STIHL MS 261 C-M professional petrol chainsaw
• Selected 16″ or 18″ Light 04 guide bar
• Matching .325″ Rapid Super Pro saw chain
• Guide-bar scabbard
• Combination tool
• Operating and safety instructions

Fuel, two-stroke engine oil, chain oil and protective equipment are not included unless specifically stated.

Maintenance and Service Kit 11

Regular servicing helps protect engine performance, starting reliability and machine life.

Routine checks should include:

• Chain tension and sharpness
• Guide-bar condition
• Chain-oil delivery
• HD2 filter condition
• Fuel filter
• Spark plug
• Chain-brake operation
• Starter mechanism
• M-Tronic operation and calibration

STIHL Service Kit 11 contains an HD2 air filter, spark plug and fuel filter for compatible MS 261 and MS 362 machines. Browse Masseys’ STIHL service-kit range.

M-Tronic calibration procedures vary by the generation fitted. Follow the machine’s operating manual or ask Masseys’ workshop for assistance rather than using a generic reset procedure.

Chainsaw safety and protective equipment

The MS 261 C-M is a professional high-speed chainsaw. It should only be operated by someone with appropriate instruction, competence and protective equipment.

Before use:

• Read the operating and safety manuals
• Understand the chain brake and kickback risks
• Inspect the timber and surrounding work area
• Check chain tension and lubrication
• Keep bystanders and animals clear
• Plan an appropriate escape route for felling work

Suitable protective equipment should include:

• Chainsaw protective trousers
• Chainsaw boots
• Eye or face protection
• Hearing protection
• Protective gloves
• An appropriate forestry helmet

Browse Masseys’ chainsaw protective trousers and wider range of chainsaw accessories and PPE.

Never operate a chainsaw from a ladder. Larger, leaning, storm-damaged or technically difficult trees require appropriate professional training, planning and equipment.

Warranty

STIHL’s standard warranty is two years for domestic use and one year for professional use, subject to current terms, correct application and maintenance.

Qualifying professional customers can extend the warranty from one to two years when purchasing the machine with an eligible STIHL Smart Connector and having the extension registered by the STIHL Approved Dealer at the point of sale.

Why buy the STIHL MS 261 C-M from Masseys?

Masseys is a STIHL Authorised Dealer based in Woodville, near Swadlincote.

Every petrol chainsaw sold by Masseys is assembled, inspected, test-run and registered by our trained team before handover.

Buying from Masseys gives you access to:

• Help choosing between the 16-inch and 18-inch versions
• Advice comparing professional forestry and landowner saws
• Genuine UK STIHL machinery and cutting attachments
• Product preparation and operating guidance
• Warranty registration and support
• Replacement Light 04 bars and RS Pro chains
• Fuel, two-stroke engine oil and chain oil
• M-Tronic diagnosis and workshop support
• Chain sharpening and replacement parts
• Local collection and delivery options

Our garden machinery servicing and repairs workshop can assist with servicing, M-Tronic diagnosis, repairs, chain sharpening and genuine STIHL parts.

For help selecting the correct bar length or confirming product identifiers, please contact Masseys before ordering.

Frequently asked questions

What engine does the STIHL MS 261 C-M have?

It uses a 50.2 cm³ STIHL 2-MIX petrol engine producing 3.0 kW / 4.1 hp.

How much does the MS 261 C-M weigh?

The powerhead weighs approximately 4.9 kg without fuel, guide bar or saw chain.

Is the MS 261 C-M a professional chainsaw?

Yes. It is a professional forestry chainsaw designed for felling, snedding, thinning, timber processing and intensive tree-maintenance work.

What does M-Tronic do?

M-Tronic automatically regulates ignition timing and fuel metering, accounting for factors including temperature, altitude, fuel quality and engine operating conditions.

Does M-Tronic need manual carburettor adjustment?

Normal manual carburettor tuning is not required. The system automatically manages fuel delivery, although recalibration or dealer diagnosis may occasionally be needed after servicing or if performance changes.

Should I choose the 16-inch or 18-inch version?

Choose the 16-inch version for lower front-end weight and easier manoeuvrability. Choose the 18-inch model when additional guide-bar reach is regularly required.

Is the 18-inch version more powerful?

No. Both versions use the same 50.2 cm³, 3.0 kW powerhead. Only the guide bar and matching chain length change.

Which saw chain does it use?

The current cutting system uses a .325″ STIHL Rapid Super Pro chain with a 1.3 mm drive-link gauge.

What is the difference between the MS 251 and MS 261 C-M?

The MS 261 C-M produces 3.0 kW from a 4.9 kg professional powerhead and includes M-Tronic. The MS 251 produces 2.2 kW from a 4.8 kg domestic powerhead and uses a conventional carburettor.

Is the MS 291 more powerful?

No. The MS 291 has a larger engine but produces 2.8 kW, compared with 3.0 kW from the MS 261 C-M. It is also substantially heavier.

What fuel does it use?

It uses a 50:1 mixture of suitable petrol and approved two-stroke engine oil. STIHL MotoMix ready-mixed fuel can also be used.

Does it need separate chain oil?

Yes. Dedicated chainsaw chain oil must be added to lubricate the guide bar and saw chain.

Can the oil delivery be adjusted?

Yes. The oil-pump setting can be adjusted to suit the cutting attachment and operating conditions.

Which service kit fits the MS 261?

STIHL Service Kit 11 is designed for compatible versions of the MS 261 and MS 362. Check the machine number before ordering.

Can Masseys service M-Tronic chainsaws?

Yes. Masseys’ on-site workshop can assist with M-Tronic diagnosis, calibration, servicing, repairs, replacement parts and chain sharpening.