The way I ended up with the McCulloch CS 50S is that I had spent two seasons being mildly frustrated by the CS 42S on the larger material. Not on the standard jobs, those it handles fine, but anything above 14 inches in diameter in a single pass and the 42 cc engine starts to let you know it is working harder than it would like. I wanted to move to the 18-inch bar without moving to a Husqvarna or a Stihl at the equivalent price, and the CS 50S was the obvious place to start looking given I already had some experience with what the 42S could and couldn’t do.

The CS 50S is McCulloch’s bigger petrol saw: 50 cc, 2.1 kW, 46 cm bar with 0.325 inch chain pitch, 24.1 metres per second chain speed, 5.9 kg without bar and chain. It shares the same OxyPower engine platform and Husqvarna AB ownership as the CS 42S, and the family resemblance is obvious in the hands. The Sure Fire Start system and Auto Return Stop Switch are improvements over the CS 42S’s starting setup, and the felling sights moulded into the casing are a practical addition you notice the first time you make a felling cut and do not have to guess the angle. It is available on Amazon UK and from the major online UK garden machinery retailers, fully assembled out of the box.

What the step up from the CS 42S actually gives you

The power difference between 1.5 kW and 2.1 kW is a 40% increase, and on larger material that is not an abstract number. The first time I ran the CS 50S through an ash trunk at around 16 inches in diameter, cutting from one side rather than two, the engine did not bog or strain. It went through at a pace that the CS 42S would not have managed without stopping and starting and cutting from both sides. The chain speed at 24.1 metres per second also exceeds the CS 42S’s 20 metres per second, and the difference is perceptible on softwood. The fuel tank is 0.425 litres versus the CS 42S’s 0.3 litres, and on a full morning of mixed cutting I could typically complete the session without a refuel, whereas the same morning on the CS 42S had me filling up at least twice.

CS 42S vs CS 50S: what changes
Power output1.5 kW vs 2.1 kW (+40%)
CS 42S: 1.5 kWCS 50S: 2.1 kW
Chain speed20 m/s vs 24.1 m/s (+20%)
CS 42S: 20 m/sCS 50S: 24.1 m/s
Fuel tank0.3 L vs 0.425 L (+42%)
CS 42S: 0.3 LCS 50S: 0.425 L
Weight (bare)4.9 kg vs 5.9 kg (+1 kg)
CS 42S: 4.9 kgCS 50S: 5.9 kg

Specifications and scores

Product review
★★★★☆
McCulloch CS 50S
3.7
out of 5
overall score
Performance scores
Cutting performance
3.8 / 5
Fuel life
3.5 / 5
Build quality
3.3 / 5
Ease of use
3.7 / 5
Value for money
3.9 / 5
UK suitability
3.5 / 5
Full specifications
Engine
50 cc OxyPower two-stroke
Power output
2.1 kW / 2100 W
Chain speed (max)
24.1 m/s
Bar length
46 cm / 18″ (15-18″ compatible)
Chain pitch
0.325″
Weight (bare)
5.9 kg
Fuel / oil tank
0.425 L / 0.295 L
Fuel mix
50:1 (min 92 RON petrol)
Sound power (LWA)
122 dB
Vibration (equivalent)
7.76 m/s²
Oil pump
Automatic
Warranty UK
1 year
Step-up domestic petrol chainsaw
McCulloch CS 50S Petrol Chainsaw
★★★★☆ 3.7 / 5
Engine50 cc OxyPower
Bar46 cm / 18″
Weight5.9 kg bare
Warranty1 year
View on Amazon
As an Amazon Associate I earn from qualifying purchases.

Starting, handling and what it feels like to use

The Sure Fire Start system is a different setup from the CS 42S’s starting arrangement. The Soft Start cord resistance reduction of up to 40% is still there, but the combined choke and stop controls and the Auto Return Stop Switch work together to make the starting sequence simpler and less likely to end with a flooded engine. On a cold morning it starts in three to four pulls. On a warm engine it picks up faster than that. I have not had a cold-start problem with the CS 50S that I could not trace back to fuel that had been sitting longer than it should have.

At 5.9 kg it is a kilo heavier than the CS 42S, which is noticeable but not punishing. Over a two-hour session felling and processing medium-sized trees in the back field, my arms and shoulders were the thing that called a halt rather than the saw. The anti-vibration system isolates the handles from the engine and cutting unit, with an equivalent vibration figure of 7.76 m/s² from the manual. That is higher than the Husqvarna 435 II, which sits at 3.1 and 3.8 m/s² on front and rear handles respectively. Over a sustained session the difference accumulates in the palms.

The inertia chain brake stops the chain if kickback trips the front guard, and confirming it engages before each session takes about ten seconds with the engine running. The felling sights are moulded into the casing, giving two reference lines for checking cut direction. I had not used a saw with these before and assumed I would find them unnecessary. They are not unnecessary. The CCS centrifugal pre-cleaning system works on the same principle as the CS 42S: large particles are ejected before they reach the main filter, extending service intervals.

Performance on the jobs I used it for
16″
ash, one side
No bogging, consistent pace
The CS 42S would have needed to cut from both sides. The CS 50S went through cleanly in a single pass at a working pace, engine not labouring.
2 hr
felling session
Arms before engine
On a two-hour felling and processing session, fatigue in arms and shoulders called the halt, not the saw. One refuel was enough for the full session.
7.76
m/s² vibration
Noticeable on extended sessions
Higher than the Husqvarna 435 II (3.1/3.8 m/s²). Over two hours it accumulates. For occasional half-day sessions it is manageable. For daily professional use it is the argument for a better-damped saw.
3-4
pulls cold start
Sure Fire Start works as described
With fresh 50:1 fuel and the correct starting sequence, three to four pulls on a cold engine. Warm starts significantly faster. No cold-start issues when fuel is correctly mixed and fresh.
💡

Check the chain tensioner before you start. The manual side tensioner requires a tool. Chain tension loosens over a session, especially on a new chain. Check before you begin and check again after the first ten minutes of cutting.

The fuel rule and why it matters even more at this size

The manual is clear: 50:1 mix, minimum 92 RON petrol, quality two-stroke oil for air-cooled engines. For the CS 50S sitting in a shed between sessions of serious use, getting the fuel discipline right matters more than it does for an occasional-use light saw, because the sessions are longer and the saw is working harder when you use it. A carburettor problem on a saw this size is worth more in repair cost than on the CS 42S, which is already tight at 1 year warranty. The McCulloch OxyPower engine offers 70% fewer emissions and 20% less fuel consumption than previous models, but the fuel system is still petrol and still subject to ethanol degradation and seal damage when old mix is left to sit.

Fuel and storage: priority order
Essential
Always use 50:1 fresh mix, min 92 RON
Standard pump petrol with ethanol content degrades in the tank and damages seals and the carburettor. The carburettor is not owner-adjustable. A contaminated carburettor is a dealer visit at your cost.
Essential
Run the saw dry before any storage
Let the engine run until it stalls from fuel starvation after each session. Leaving fuel in over winter is the single most common cause of starting failure and carburettor problems on any petrol chainsaw.
Recommended
Use alkylate pre-mix for long storage periods
If the saw will sit for more than a few weeks, alkylate fuel is more stable than standard pump petrol and significantly kinder to rubber components in the fuel system. Worth the extra cost for an infrequently used saw.
Recommended
Mix only what you need; do not store old mix
The manual specifies purchasing fuel in quantities that can be used within 30 days. Mixed two-stroke fuel degrades. Mix fresh for each session rather than keeping a can of old mix in the garage.
Optional
Add a fuel stabiliser for seasonal storage
The manual recommends adding a stabiliser if the saw will sit for a season. Run the engine for at least 5 minutes after adding stabiliser to distribute it through the fuel system before storage.

Performance, limitations and who it is for

On the material I have used it for, the CS 50S performs well for a budget petrol chainsaw. Medium-sized trees up to about 16 to 18 inches in diameter, firewood processing, clearing work: it handles these tasks without drama. The 46 cm bar gives more headroom than the CS 42S on larger-diameter material, and the 2.1 kW engine makes a real difference on hardwood. The plastic housing is the same concession to price as on the CS 42S: it looks less robust than the equivalent Husqvarna or Stihl, and a drop or rough handling is more of a concern. The saw is priced accordingly.

The sound level from the manual is 122 dB LWA, which sits in the range for a petrol chainsaw of this size. Ear protection is not optional. The CS39 chainsaw certificate applies for professional or employed UK buyers at this chain speed. Domestic buyers have no legal purchase restriction. The 1-year warranty is still the number to sit with before buying, same as with the CS 42S.

Pros and cons
Pros
  • 2.1 kW / 50 cc: genuine step up over the CS 42S on large material
  • 18″ bar handles medium trees and firewood above 14″ more comfortably
  • Larger fuel tank (0.425 L) reduces refuelling interruptions
  • Felling sights: useful for precision cuts, absent on CS 42S
  • OxyPower: 70% less emissions, 20% less fuel vs previous generation
Cons
  • 1-year warranty only; Husqvarna and Stihl equivalents offer 2 years
  • 7.76 m/s² vibration: higher than premium alternatives
  • 1 kg heavier than CS 42S; 5.9 kg bare
  • Plastic housing; chain tensioner requires tool
  • Same fuel discipline required as any petrol saw
Who it’s for and who it’s not for
Who it’s for
  • CS 42S users who found its power ceiling frustrating on larger material
  • Medium-sized tree felling, firewood above 14″, regular half-day sessions
  • Budget buyers wanting 50 cc capability without moving to premium brands
Who it’s not for
  • Professional or daily use; vibration and warranty both argue against
  • Anyone not willing to maintain correct fuel discipline every session
  • Anyone who would be better served by the longer warranty and lower vibration of the Husqvarna 435 II

Verdict: the bigger McCulloch, and whether it is worth it

The CS 50S is a better saw than the CS 42S in every specification that matters for larger work: more power, bigger bar, faster chain, larger fuel tank. The things that stayed the same are the things you would want to have improved: the 1-year warranty, the plastic housing, the manual chain tensioner that needs a tool. These are not surprises. They are the price of the price.

For the person who cuts two or three cubic metres of firewood a year, clears occasional storm damage, and takes down a small-to-medium tree once or twice a season, the CS 50S does the work. It starts reliably when the fuel is right, the Sure Fire Start system is an improvement over the older setup, and the felling sights are a more useful addition than they might sound. The extra kilo over the CS 42S is real but manageable for the kind of sessions this saw is built for.

The one-year warranty is still the number to sit with before buying. Use fresh 50:1 fuel, run it dry before storage, keep the chain at the right tension, clean the filter regularly, and the saw performs the domestic jobs it is built for without drama. The CS 50S is capable. The discipline it requires is just the discipline any petrol chainsaw requires.

Our verdict

A capable step up from the CS 42S for anyone who was finding the smaller saw’s engine a limitation. The 50 cc OxyPower engine handles larger material comfortably, the fuel tank lasts longer, and the felling sights are a practical improvement. The 1-year warranty and higher vibration are the consistent trade-offs in this price bracket. For occasional domestic use with correct fuel discipline, it does the job.

“The first time I ran it through 16-inch ash in a single pass, it went through at a working pace and the engine did not complain. That was the point.”
Step-up domestic petrol chainsaw
McCulloch CS 50S Petrol Chainsaw
★★★★☆ 3.7 / 5
Engine50 cc OxyPower
Bar46 cm / 18″
Weight5.9 kg bare
Warranty1 year
View on Amazon
As an Amazon Associate I earn from qualifying purchases.

Share on socials: