Stihl FS 38 Review – UK Tested

I hadn’t really planned on doing the edges that Saturday, but the trimmer was already out and it seemed daft not to while it was there. Twenty minutes later they were done, nothing dramatic about any of it, light enough in the hand that I’d more or less forgotten I was carrying it by the time I finished.

This is a 27.2cc two-stroke weighing 4.1kg dry without the cutting attachment or deflector fitted.

Overview and first impressions

The loop handle turns through a full 360 degrees and the single multi-function control sits right under your thumb, simple enough that switching hands or being left or right handed never once got in the way.

Specifications and scores

The AutoCut C 6-2 head takes 2mm line as standard, and Stihl don’t allow metal cutting tools on this model at all, which rules out the upgrade path some rivals offer. At your ear it measures 94dB(A), and noise gets measured two different ways on the paperwork beyond that.

How it performed in our tests

Starting it cold took a proper run through the steps every single time, choke up, prime the fuel pump at least five times, a slow pull to feel the resistance before the real yank. Once warm it caught quicker, though I never quite trusted it the way I trust tools that start the same regardless of mood. A few sessions it fired second pull. A few others it took closer to ten or fifteen before it settled into a proper idle, and on one particularly cold morning I gave up, left it twenty minutes, and it started clean on the first go once it had warmed through.

The engine itself has real bite once it’s running, more than the weight suggests, but it bogs down noticeably the moment you push into anything thicker than ordinary lawn edge grass. Easing off rather than forcing it through kept things running, forcing it just stalled the thing outright more than once.

Swapping the standard head for a PolyCut let me get through some proper overgrown weeds at the back of the plot that the line alone wouldn’t have managed, though Stihl are explicit that’s meant for clear, unobstructed edges without posts or fencing nearby, not the cluttered corners I’d have liked to use it on.

Fuel system and maintenance

There’s no battery on this one, just a 330cm³ tank and a 1:50 petrol to two-stroke oil mix that needs measuring properly rather than guessed at. I keep mine made up in small batches now since the mix genuinely goes off if it sits around more than 30 days, faster still if it’s somewhere warm or in direct light.

The first three tanks are meant to run gently, no full throttle without a load, while everything inside beds in. It took mine closer to ten tank fills before it stopped feeling like it was holding something back, longer than I’d expected for something this size.

I wear gloves and take proper breaks now without really thinking about it, not because of anything dramatic but because Stihl are specific that cold hands and a tight grip on the handles shorten how long you can safely use something this size of engine for, and I’d rather build the habit than find out the hard way. The risk has a name, whitefinger disease, vibration affecting circulation in the fingers and hands, and the advice if tingling or numbness ever shows up is to stop and see a doctor rather than carry on regardless.

Performance and limitations

What this does well is exactly what Stihl built it for, tidy edges and borders on an ordinary garden, light enough that an afternoon of it never left my arms complaining the way a heavier machine would have.

The honest limitation is the line feed, and I won’t pretend it’s consistent. Some sessions it just works. Others it’s the reason the job takes twice as long as it should, stopping repeatedly to sort the spool out by hand rather than getting on with the actual trimming.

Build quality isn’t always a given either. Someone on the same allotment site had the blade guard snap clean off the first time they used theirs, the head jamming constantly after, and getting Stihl or the seller to even reply took weeks. Mine’s never given me that kind of trouble, but it’s worth knowing it can happen.

Cold starting needs patience too, and the line feed having an off day is something to plan around rather than rely on. None of that’s a surprise once you know it’s coming, but it’s worth knowing before the first job rather than during it.

Final verdict

This earns its place for exactly the job Stihl built it for and nothing more. Light, manageable, fine on ordinary lawn edges and borders, the kind of trimming most gardens actually need most of the time.

Push it past that, thicker growth, a line feed having an off day, a cold morning start, and the limits show up fast. None of that’s hidden or unexpected once you know the trimmer for what it is.

For tidy edges on a normal garden, this does the job. For anything more demanding, look further up Stihl’s own range before assuming this one will stretch to cover it. Buying a Smart Connector alongside it stretches the standard warranty by another year too, worth doing at the same time rather than as an afterthought.