Stihl / Gas / Farm & Ranch

Stihl MS 311

Name: Stihl MS 311
Brand: Stihl
Price: 760 USD
Availability: InStock

50cc class

59cc

Engine

3.1 kW rated

18 in

Bar

cuts to about 16 in

13.8 lb

Weight

powerhead only, without fuel (16.7 lb with the 18" bar and chain)

~$760

approx., with 18" bar and chain

See it at Stihl

Price and availability on Stihl's site may differ.

Here is the problem with the MS 311, and owners state it bluntly: it weighs exactly what the MS 391 weighs — 13.8 lb of powerhead — while making 0.2 kW less from 5cc less engine, for the same $760. Unless a dealer has one discounted, the 391 is the same saw with a bigger cylinder. On its own terms the 311 is a competent 59cc farm saw with 3/8" .050" gearing, bumper spikes, pre-separation air filtration and a side-access tensioner, and owners running 16-inch bars and hand-filed full-chisel chain report cutting serious volumes of firewood with it. Push it to a 20-inch bar in hardwood and it bogs. Power-to-weight is the recurring criticism in long-term threads, along with how much of the saw is polymer for the money.

Best for: Farm and acreage owners who find an MS 311 discounted below the MS 391 and will keep a 16- or 18-inch bar on it.

Specifications

Engine class: 50cc class (by displacement)
Engine: 59 cc
Rated power: 3.1 kW
Bar length: 18 in
Bar range: 16-25 in
Single-pass cut: about 16 in (bar minus 2)
Chain: 3/8" pitch / .050" gauge (33 RS3)
Weight: 13.8 lb, powerhead only, without fuel (16.7 lb with the 18" bar and chain)
Power type: Gas
Use case: Farm & Ranch
Warranty: 1-year consumer / 3-month professional (Stihl policy effective Jan 1, 2026)
Model: MS 311

Manufacturer figures except the engine class and single-pass cut, which are derived here. What each spec means

59cc, 3.1 kW
Same 13.8 lb as the MS 391
IntelliCarb air-flow compensation

What owners like

3/8" .050" chain and bumper spikes — proper felling and bucking gearing, not homeowner narrow-kerf
Pre-separation air filtration stretches filter intervals noticeably in dry, dirty cutting
IntelliCarb compensates as the air filter loads, so mixture does not drift rich during a long day
Owners report high firewood output with a 16" bar and a well-filed full-chisel chain
Side-access tensioner and toolless caps make bar swaps quick

Common complaints

Same 13.8 lb powerhead as the MS 391 for less power at the same list price — hard to justify at full retail
Bogs in hardwood with a 20" bar; 16-18" is where it actually works
Owners repeatedly call the power-to-weight poor and the saw plastic-heavy for the money
No M-Tronic at $760 — you still tune the carburetor for altitude and season

What owners say

Read from owner discussions, long-term write-ups and dated retail reviews; nothing here was measured on this site.

The 311 is a 59cc farm saw that owners treat as competent rather than good. It runs a 3/8 .050 chain, takes bars from 16 up to 25 inches, and in the hands of someone cutting storm damage and a few cords a year it does the job and keeps doing it — the most-upvoted comment about it is simply that it will last a lifetime of seasonal cutting if you take care of it. Owners who criticise it hardest still concede that point. It is also easy to work on: open the muffler, tune the carburetor, keep it clean.

The complaint everyone arrives at is power-to-weight. Owners of the saw itself call it among the worst in the Stihl range — one replaced his with a 500i after it struggled on a 25-inch bar in old-growth oak and says he would buy a 261 instead given the chance; a sawyer who learned on one says a 261 pulls a 20-inch bar about as well while being significantly lighter. A landowner clearing twelve acres of nine-inch scrub says he loves his and it still wears him out. Two mechanical complaints recur alongside that: flooding and hard cold starts (one owner on his second 311 regrets trading an MS 290 for it), and the sealed clamshell. A rebuilder documented the transfer side covers held by sealant with no bolts and lost a saw mid-cut after three years of seasonal use with a clean bore; others, including a Stihl mechanic of eleven years, say the design has been used for decades and is fine when assembled properly, and that a failed cover can be repaired with a die grinder, liquid metal and 24 hours in a vise.

Where it makes sense is narrow. Keep a 20-inch bar on it, and if you cut clean wood, convert it to .325 pitch with an Oregon drum and an eight-pin rim — the owners who have done it report it pulling noticeably easier and cutting smoother, though in dirty wood 3/8 is the better choice. A muffler mod and tune is the other upgrade owners rate, with the warning that it leaves the saw lean and much louder. The hard part is the price. Owners note the 311 is effectively the MS 391 with a 2mm smaller piston at the same weight, so at full list you are paying for less power in the same chassis; the saw only clearly makes sense discounted. Against the rest of the market the recurring answers are an Echo CS-590 or 620 for less money with a five-year non-commercial warranty, a Husqvarna 460 Rancher as the direct equivalent, and a 261 or 362 if you would rather have a lighter saw that can be rebuilt.

What owners like

The most upvoted defence of it is that it outlasts the argument: a well-maintained 311 will give a lifetime of seasonal cutting, and owners who use it that way do not come back complaining. One bought his for storm damage with intermixed felling and reports a year of trouble-free use with a 20-inch bar that he says does not overwork the powerhead. Even the owners who criticise it hardest add the same caveat — it is not a bad saw, it will run forever if you look after it, and the disappointment is only relative to a pro saw.
It is straightforward to work on and it responds well to being opened up. The short version owners give is: open the muffler, tune the carburetor, keep it clean, and it will last. One owner did a DIY port job on the cylinder combined with an aftermarket power port on the stock muffler and reports a large gain in cutting speed and throttle response. The people who have done it are careful to add the steps — the carburetor limiter tabs have to come off, and the saw runs lean after a muffler mod, so it needs richening or you will cook the piston, and it gets considerably louder.
Converting it from 3/8 to .325 pitch is the cheap change owners recommend most. One fitted an Oregon clutch drum with a .325 eight-pin rim and a 20-inch bar and says it pulls noticeably easier and cuts faster and much smoother, with the honest caveat that this only holds in clean wood and a sharp chain — in dirty wood you are better off leaving it in 3/8.
It will handle an occasional big tree, which is the one thing that separates it from the 50cc saws. Twenty-five inches is the longest bar Stihl offers for it, and an owner who put one on for a large oak reports it used literally the entire bar and did the job, as long as you let it cut rather than leaning into it. The other thing worth knowing is that this saw gets discounted — one buyer picked one up for around $497 against a $660 list, and at that gap the usual advice to skip it stops applying.

Common complaints

Owners put its power-to-weight among the worst in the Stihl range, and the harshest verdicts come from people who own one. One says exactly that, then explains he replaced it with a 500i because the 311 struggled to run a 25-inch bar in old-growth oak, and that if he were choosing again he would buy an MS 261. A sawyer who learned to cut on one before moving to pro saws says it is very heavy for the power it makes and that a 261 pulls a 20-inch bar about as well while being significantly lighter.
It is tiring over a full day in small wood. An owner clearing twelve acres of privet and scrub — nothing wider than nine inches — says he loves the saw but it wears him out, and he went looking for something several pounds lighter rather than more powerful. Owners describe it as a big clamshell in the same bracket as a Husqvarna 460 Rancher: fine for farm use and occasional firewood, and if you are doing more than that you want a 362.
Cold starting and flooding are the complaints that repeat. One owner on his second 311 calls it hard to start and says it floods very easily, and regrets replacing an MS 290 with it — along with the old workshop adage about avoiding Stihl models whose number ends in 1. Another found the decompression valve popping on every pull after four months of storage. The repair threads add defective carburetors, air leaks after a top-end replacement, and at least one saw that arrived from the factory or a prior repair missing the heat shield between muffler and cylinder.
The sealed clamshell is the design argument against it, and it is genuinely contested. A rebuilder posted photographs showing the transfer side covers held on by sealant with no bolts, calls the combustion chamber glued together, and notes the aftermarket Hyway rebuild kit includes bolts while the factory kit does not — his saw died mid-cut after three years of seasonal use with a perfect-looking bore. Another who assembled one from a box of parts says it is a terrible design and prone to air leaks. The dissent is equally specific: owners who have rebuilt 30-year-old saws built the same way say the RTV-sealed clamshell is fine when it was assembled correctly, and a Stihl mechanic of eleven years gives the repair — dress the cylinder and cover edges with a die grinder, apply liquid metal and leave it clamped in a vise for 24 hours.
At full retail it is hard to defend against its own bigger brother. Owners point out the 311 is essentially the 391 with a 2mm smaller piston, that a 391 cylinder bolts straight on for more power, and that the two weigh effectively the same — so paying list for the smaller one buys you the same saw making less power. Unlike the 6-series saws, the case cannot be split and serviced. The cross-shopping answers that come up most are an Echo CS-590 or 620 for less money with a five-year non-commercial warranty, and a 362 or 400 if you are cutting often enough to care.

Questions owners ask

My chain will not hold tension — it goes too loose or too tight no matter what I do. What is wrong?

Owners work through this in a fixed order. First, mismatched gearing: running .325 chain on 3/8 hardware, or 3/8 low-profile where regular 3/8 belongs, means the chain will never tension correctly or run smoothly, and shop techs say they see saws delivered to the bench exactly like that. Second, technique: lift the bar tip while you tighten, set tension with the adjuster, then tighten the bar nuts fully — the tensioner only holds the chain while the nuts go down. Third, a chain that has been over-tensioned repeatedly stretches and develops tight and loose spots, so it reads as both problems at once; tension it at the tight spot and replace it when it reaches the wear marks. If none of that holds, owners point at a worn or shot tensioner with play in it, or a damaged bar.

Is the sealed clamshell really going to kill the saw?

Opinions genuinely split here. The case against comes from a rebuilder who photographed the transfer side covers held on by sealant with no bolts and whose saw died mid-cut after three years of seasonal use with a bore that still looked perfect, and from another owner who assembled one from a box of parts and considers it prone to air leaks. The case for comes from owners who have rebuilt 30-year-old saws built the same way and say the RTV-sealed clamshell lasts a lifetime if it was assembled correctly at the factory. The practical middle ground is the repair a Stihl mechanic of eleven years gives: clean the cylinder thoroughly, dress the cylinder and cover edges with a die grinder, apply liquid metal and leave it clamped in a vise for 24 hours. If the saw starts running lean or revving on its own, pressure and vacuum test it before you touch the carburetor.

How much bar will it actually pull?

Twenty inches is where owners say it works, and 25 inches is the longest bar Stihl offers for it. One owner ran a 25-inch bar through a large oak and reports it used the whole bar and did the job, provided you do not force the cut; another who went to 25 inches in old-growth oak found it struggling badly enough that he replaced the saw. If you want 25 inches to work, owners say use a full skip chain to keep chain speed up. For hardwood day to day, keep it at 16 to 20 inches.

Is the muffler mod or the .325 conversion worth doing?

Owners rate both, with conditions. The .325 conversion — an Oregon clutch drum, a .325 eight-pin rim and a 20-inch bar — is described as pulling noticeably easier and cutting faster and much smoother, but only in clean wood with a sharp chain; in dirty wood owners say stay in 3/8. The muffler mod gains are real but, in the words of one owner who did it, not earth-shattering. It is also not a bolt-on: you have to remove the carburetor limiters and shave the limit tabs, and the saw will run lean afterwards and needs richening or you risk the piston and cylinder. It gets considerably louder too. One owner who combined a DIY port job with an aftermarket power port on the stock muffler reports the biggest change of anyone.

MS 311, MS 391, or step up to a 261 or 362?

At similar money owners almost always point away from the 311. The 391 is the same chassis with a bigger piston at effectively the same weight, so if the two are close in price the 391 is the better value — and owners note a 391 cylinder bolts straight onto a 311. If you want a lighter saw you will enjoy using, the MS 261 is the recommendation that comes up most, and owners say it pulls a 20-inch bar about as well while being several pounds lighter. If you are cutting often, the answer is a 362 or 400, which can be split and rebuilt as parts wear. For pure value, the Echo CS-590 or 620 comes up repeatedly at lower cost with a five-year non-commercial warranty, and the Husqvarna 460 Rancher is the direct equivalent.

Drawn from 8 owner threads and long-term reviews, kept on file with this entry.