Stihl MS 170 vs. MS 171 Chainsaw (Field Test)
The MS 170 and MS 171 are both light-duty homeowner saws, but the MS 171 has a small power advantage: about 31.8 cc and 1.3 kW versus 30.1 cc and 1.2 kW for the MS 170. That difference is modest. Choose by condition, exact setup, workload, and dealer support, not by the model number alone.
I compare these saws by asking what work they must do, then checking the saw’s actual configuration against its manual. That matters with used equipment: the bar, chain, and parts may differ by market and year, even when the model name is the same. A higher model number also does not turn a homeowner saw into a professional felling saw.
For a property owner cutting small limbs, bucking modest firewood, or doing occasional light maintenance from the ground, either may fit. Neither is a substitute for a larger saw when the wood, site, or cut exceeds the saw’s safe capacity. The operator’s training and the tree’s condition matter as much as engine size.
MS 170 vs. MS 171 specifications and key differences
This comparison covers the main published engine figures and the setup details that affect a real purchase. Specifications can vary by country, production year, and configuration, so treat the saw’s nameplate and model-specific STIHL manual as the final reference.
| Feature | MS 170 | MS 171 |
|---|---|---|
| Engine displacement | 30.1 cm³ | 31.8 cm³ |
| Approximate engine power | 1.2 kW / 1.6 bhp | 1.3 kW / 1.7 bhp |
| General category | Light-duty homeowner saw | Light-duty homeowner saw |
| Common chain pitch | 3/8 in Picco (3/8 P) | 3/8 in Picco (3/8 P) |
| Typical bar range, where approved | Often 30–40 cm (12–16 in) | Often 30–40 cm (12–16 in) |
The MS 171’s displacement is 1.7 cm³ greater, and its approximate power rating is 0.1 kW higher. That is a small difference, not a clear jump to a more demanding work class. In practice, a sharp, correctly matched chain and a sound saw can matter more than that gap.
Bar range is not a universal rating. Confirm what STIHL approves for the exact model and market, then use the shortest bar that reaches the cut safely. Hardwood does not have one simple “safe” diameter or bar-length rule. Wood condition, lean, tension, compression, and the operator’s escape route all affect the job.
Which saw fits your work?
Use this guide as a starting point, not permission to attempt a cut beyond your training. Both saws suit modest ground-level property work when the saw is in good condition and the cut is within its capacity.
| Your job | Practical choice |
|---|---|
| Occasional pruning from the ground and small-wood bucking | Either saw may suit |
| Choosing between two similarly maintained saws | The MS 171 has a slight published power edge |
| Frequent, large-diameter, or demanding cuts | Reassess the saw class; these models may not fit |
| Used saw with unclear parts or service history | Verify configuration and condition before buying |
Field comparison: what the small power gap means
A field comparison should look at the whole cutting setup, not just the engine figures. I focus on whether the saw starts, idles without moving the chain, oils the chain, and cuts smoothly with a sharp chain. Those checks help separate a genuine model difference from a worn or poorly maintained saw.
In a like-for-like comparison, the MS 171’s small power advantage may help it maintain cutting progress under similar conditions. It does not guarantee a faster cut: chain sharpness, chain tension, bar condition, wood type, and operator technique can change the result. A dull chain should be sharpened, not forced through the wood.
On a used saw, condition can outweigh the model-year difference. Before comparing prices, inspect the bar and chain, check for damage or unusual wear, and ask about service history. If the seller cannot confirm the saw’s setup, treat that as uncertainty, not as evidence that the parts are correct.
A useful field check is to compare only saws in similar condition and configured according to their manuals. Do not change carburetor settings to make one saw seem stronger. STIHL manuals commonly give an idle speed near 2,800 rpm and a maximum engine speed near 10,000 rpm for these models, but confirm the exact manual revision. Do not adjust by ear or exceed the stated maximum.
Equipment setup and safety preparation
Safe work starts before the engine does. Wear suitable personal protective equipment, inspect the saw’s safety parts, prepare the site, and follow the manual’s starting procedure. If the chain brake, throttle lockout, chain catcher, or stop switch does not work as intended, stop and have the saw checked.
Use a properly fitted helmet with face and eye protection, hearing protection, chainsaw-rated leg protection, gloves, and protective boots. Clear bystanders and obstacles from the work area. Assess the tree or wood, identify hazards, plan each cut, and set an escape route before starting. Follow applicable workplace rules, including OSHA requirements where they apply, and relevant guidance such as ANSI Z133.
For a cold or warm start, follow the model’s manual and keep the chain brake engaged. Start on stable ground with the chain clear of the ground and nearby objects. After starting, check that the chain stops at idle, the brake works, and the chain receives oil as directed. Stop work if any check fails.
Use fresh gasoline that meets the manual’s requirements, mixed with STIHL two-stroke oil at 50:1. These saws do not use a separate engine-oil reservoir. Do not use straight gasoline or premix unless you have verified the oil ratio and fuel condition. Incorrect fuel can damage the engine.
Match the bar and chain before buying parts
“Chain pitch” is the spacing standard between chain links, while “gauge” is the thickness of the drive links that fit into the bar groove. The pitch and gauge must match the bar, chain, and sprocket; the drive-link count must also fit the bar. Do not order a chain by model name alone.
The common pitch is 3/8 in Picco, but gauge and drive-link count depend on the installed package. Examples of chain gauge include .043 in and .050 in. Read the bar stamp and confirm the manual or dealer’s part information before ordering. The wrong combination can fail to fit or run correctly.
Field use: two practical property scenarios
These scenarios show how I would decide between the models without treating either as a promise of safe capacity. The right answer depends on the wood, the saw’s condition, and the operator’s skill. A difficult tree or uncertain cut calls for a qualified tree-care professional.
Scenario 1: Small branches and occasional bucking. A homeowner has modest material to cut from the ground and both saws are in comparable condition. Either model may be suitable if its bar and chain match the manual. The MS 171 has slightly higher published power, but that alone may not justify paying more for a worn example.
Scenario 2: A larger trunk with lean or binding risk. The owner is considering a longer bar to reach through the trunk. Bar length does not make this a suitable job: lean, tension, compression, and escape planning matter. If the cut may bind, the tree is unstable, or the work requires felling skill the operator lacks, stop and seek trained help rather than forcing either saw.
For every cut, keep a firm two-handed grip and a stable stance. Keep the bar nose clear of wood and obstructions. Contact with the upper quadrant of the bar nose can cause rotational kickback, which can throw the bar rapidly toward the operator. Do not cut above shoulder height, and do not rely on the chain brake as a substitute for safe technique.
Maintenance, chain sharpening, and service checks
Regular checks help both saws perform as designed, but service settings and parts must match the exact model. Use the manual for chain tension, service intervals, and adjustment procedures. A chain-specific filing gauge is the right way to set depth gauges; one clearance value should not be treated as universal.
Before work, inspect the chain, bar, brake, controls, and lubrication system. Keep the chain sharp and correctly tensioned. Use suitable bar-and-chain oil and check lubrication as directed by the manual; do not assume a fixed user-set oil-flow rate or a universal oil viscosity.
If the chain binds or the saw struggles, stop and reassess the cut. Do not push harder or keep cutting with a dull chain. After use, switch off, let the chain stop, and allow the saw to cool before servicing or refueling. Clean accessible air-intake and cooling areas, inspect the bar groove and oil holes, and store the saw with the chain covered.
For a used saw, ask a STIHL dealer to confirm the serial-number configuration and suitable replacement parts when the history is unclear. A serial number can help identify a saw, but it does not prove the saw is genuine or that its current bar and chain are correct. Compare the identification on the saw with the seller’s paperwork and have a dealer inspect suspicious or altered markings.
Which one should you buy?
The MS 170 is the sensible choice when it is in good condition, fits your occasional light work, and is priced fairly. The MS 171 offers a modest power increase, which may be useful when all other factors are equal, but it remains a homeowner-class saw. Neither model should be chosen for work that exceeds its manual, your training, or the site’s safe limits.
When comparing examples, prioritize condition, correct configuration, service access, and a dealer you can reach. Ask the dealer to verify parts and service needs for the exact saw. A genuine saw with support and a properly matched chain is a better platform than a questionable bargain with unclear history.
Bottom line: choose the better-maintained, correctly configured saw that fits your work. Pay extra for the MS 171 only if its condition, support, or small power advantage makes sense for your use.
Frequently asked questions
This FAQ answers common buying and use questions about the two saws. Check the nameplate and the exact STIHL manual before relying on a specification, ordering parts, or servicing either model.
Is the MS 171 more powerful than the MS 170?
Yes. Published figures are about 1.3 kW for the MS 171 and 1.2 kW for the MS 170. Confirm the specification for your market and production version.
Is the MS 171 a professional saw?
No. Both are light-duty homeowner models. The MS 171’s small power increase does not make it a professional felling saw.
Can I use a 16-inch bar on either saw?
A 30–40 cm (12–16 in) bar is common where approved, but approval depends on model and market. Check the manual and saw configuration before fitting one.
Do the MS 170 and MS 171 use the same chain?
Not always. Pitch, gauge, drive-link count, bar, and sprocket must match. Check the bar stamp and exact parts information.
What fuel mix do these saws use?
Use fresh gasoline that meets the manual’s requirements and STIHL two-stroke oil at 50:1. Do not use straight gasoline or an unverified premix.
Does the MS 171 cut much faster?
Not necessarily. Its power rating is slightly higher, but chain sharpness, saw condition, wood, and technique can outweigh the difference.
How can I check a used saw’s serial number?
Read the identification on the saw and ask an authorized STIHL dealer to verify the model and parts configuration. A serial number alone cannot confirm that a saw is genuine or unmodified.
Can I adjust the carburetor by ear?
No. Use the model-specific manual and qualified service guidance. Do not exceed the specified maximum engine speed.
What should I do if the chain binds?
Stop cutting and reassess the wood’s compression and tension. Do not force the saw or continue if the bar is trapped.
Which model is better for occasional homeowner use?
Either may work for light, ground-level tasks when correctly configured and maintained. Buy based on condition, workload, and dealer support rather than the model number alone.
(This article was written by one of our staff writers, Elliott Fowler. Visit our Meet the Team page.)
