Stihl MS 290 Chain & File Specs (Reference Chart)
For a common STIHL MS 290 setup, use a 3/8-in standard-pitch chain, a 5.2 mm (13/64-in) round file, and the drive-link count stamped for your bar: often 60 links at 16 in, 66 at 18 in, or 72 at 20 in. Mix fresh fuel 50:1, and verify every marking before fitting or cutting.
A chain that smokes, cuts slowly, or leaves fine dust instead of chips often needs sharpening. But the file size and chain fit must match the parts on your saw, not just the model name. Bar length, chain pitch, gauge, and drive-link count all matter. Use this quick reference first, then check the markings on your installed bar and chain.
MS 290 chain and file reference chart
This chart gives common MS 290 reference specifications, not a guarantee that every saw has the same bar or chain. Replacement parts may differ, so compare the chart with the bar stamp, chain markings, and your saw’s serial-specific manual before buying or fitting a chain.
| Item | Common reference | What to verify |
|---|---|---|
| Engine displacement | 56.5 cm³ | Confirm in the manual for your saw |
| Chain pitch | 3/8 in, standard | Match the bar and sprocket |
| Chain gauge | .050 in (1.3 mm) | Match the bar groove |
| Round file | 5.2 mm (13/64 in) | Confirm the chain cutter type |
| Common 16-in bar setup | 60 drive links | Read the bar stamp |
| Common 18-in bar setup | 66 drive links | Read the bar stamp |
| Common 20-in bar setup | 72 drive links | Read the bar stamp |
| Common depth-gauge setting | 0.65 mm (0.026 in) | Use the chain-specific gauge tool |
| Fuel mixture | 50:1 gasoline to 2-cycle oil | Use fresh fuel and oil meeting STIHL requirements |
| Reference idle speed | 2,800 rpm | Use the serial-specific service procedure |
| Reference maximum engine speed | 12,500 rpm | Do not tune by ear or exceed the manual limit |
Drive links are the small tabs under the chain that run in the bar groove. Count them if the bar stamp is missing, but don’t rely on bar length alone: chains with different configurations can require different link counts. The three listed combinations are common, not universal.
Confirm the chain fits before sharpening or fitting
Pitch is the distance used to identify chain size; gauge is the thickness of the drive links. Both must match the bar, and the chain must also match the sprocket. A mismatch can cause poor fit, wear, or chain-retention problems even when the bar length seems right.
Read the pitch and gauge stamped on the guide bar. Check the required drive-link count there too, or count the links on the old chain. If the old chain is the wrong size, use the bar and saw specifications rather than copying it.
| If you find… | Check next |
|---|---|
| 3/8-in pitch | Confirm it is standard 3/8, not 3/8-in low-profile |
| .050-in / 1.3 mm gauge | Make sure the chain drive links match the bar groove |
| A different gauge or pitch | Do not fit the chart’s chain; match the stamped bar and sprocket |
| No readable bar stamp | Check the manual or confirm the bar’s exact part details |
| A different drive-link count | Buy the count specified for that bar, even if the bar length matches |
I check these three markings before putting a new chain on a saw. It prevents a common garage mistake: buying a chain by bar length alone, then finding it will not seat properly. Do not force a mismatched chain onto the bar, and do not substitute a low-profile chain for standard 3/8-in chain.
File size, filing angle, and depth gauges
A round file removes metal from the cutter’s working edge. The file size must suit the chain, while the filing angle must suit the chain’s cutter design. For the common setup in the chart, use a 5.2 mm (13/64-in) file, but verify the chain model and its maker’s filing instructions first.
Many standard cross-cut chains use a 30-degree top-plate filing angle. That is a common reference, not a universal setting for every chain. Follow the angle marked on the chain packaging or specified by its manufacturer, and use a file guide that holds the file at that angle. Don’t guess based on the saw model.
- Secure the saw and engage the chain brake before preparing to file. For filing, release the brake as directed by the saw’s manual so the chain can move by hand; wear gloves.
- Mark the first cutter you sharpen so you know when you have completed a full loop.
- Keep the file level in the guide and use smooth strokes in the specified direction. Apply even pressure and sharpen cutters on both sides.
- Keep cutter lengths as even as practical. A very short cutter can limit how much you can sharpen the others.
- Check depth gauges with the tool specified for that chain. The common reference is 0.65 mm (0.026 in), but the chain model determines the correct tool and setting.
The depth gauge is the metal projection ahead of each cutter; it controls how much wood the cutter can take. Lowering it too far can make the chain cut aggressively and harder to control. Use the matching gauge tool, follow its instructions, and do not lower the gauges by eye.
Fuel, bar oil, and engine reference
Correct fuel and lubrication protect the engine, bar, and chain. The MS 290 reference mixture is 50:1 gasoline to 2-cycle oil by volume, or 2% oil. The machine’s current manual and STIHL fuel requirements take priority if they differ from a general reference.
| Fuel amount | 2-cycle oil at 50:1 |
|---|---|
| 1 L gasoline | 20 mL oil |
| 5 L gasoline | 100 mL oil |
| 1 US gallon gasoline | About 2.6 US fl oz oil |
Use fresh, correctly mixed fuel and keep it in an approved, labeled container. Do not run straight gasoline or guess at the ratio. An incorrect mixture can cause severe engine damage, including piston or cylinder damage.
Fill the oil tank with purpose-made bar-and-chain oil. There is no single viscosity or fixed oil-flow rate that suits every temperature and bar setup. Check the reservoir and confirm oil reaches the chain using the manual’s procedure. If the chain stays dry, stop and inspect the oil supply and passages before cutting.
The chart’s 2,800 rpm idle and 12,500 rpm maximum engine speed are reference values, not instructions to adjust the carburetor. Use the serial-specific service procedure and a tachometer for tuning. Never raise the maximum speed to compensate for a dull chain.
Install, tension, and check the saw
Chain tension is the balance between keeping the drive links in the bar groove and allowing the chain to move by hand. Set it with the engine off and the saw cool, following the manual’s tensioning steps. A chain that is too loose can come off; one that is too tight can increase wear.
Before installing a chain, inspect the bar groove, oil hole, rails, sprocket, and chain links. Remove dirt from the groove and oil hole. Replace damaged parts rather than trying to correct them by tightening the chain.
- Fit only a chain that matches the bar’s pitch, gauge, and drive-link count.
- Set tension so the drive links remain engaged in the groove while the chain can still be pulled by hand with gloves.
- Tighten the bar hardware as the manual directs, then recheck tension.
- After initial operation and after the chain cools, check tension again. A new or recently adjusted chain can need a further check.
- Before cutting, confirm the chain brake, throttle lockout, hand guards, chain catcher, fasteners, and lubrication work as intended.
In the shop, a chain that seems to “fit” but sags out of the bar groove is a stop-and-check situation, not a reason to keep tightening blindly. Recheck the part numbers and markings. If the correct chain will not tension properly, inspect for wear or damage and follow the manual’s repair guidance.
Cutting, kickback protection, and storage
A correctly sharpened chain still needs safe handling and a clear work plan. Kickback can occur when the upper quadrant of the bar nose contacts wood or another object, throwing the saw rapidly upward and back. A chain brake reduces risk but cannot prevent every injury.
Wear a helmet, eye and face protection, hearing protection, chainsaw-rated leg protection, gloves, and protective boots. Keep bystanders clear, choose an escape path, and assess footing, lean, overhead hazards, and possible binding before cutting. Follow applicable ANSI Z133 guidance; OSHA 1910.266 applies to covered logging operations.
Start with the chain brake engaged and follow the manufacturer’s cold- or warm-start procedure on stable ground. Before cutting, check that the chain does not move at idle and verify the brake and oiling function. Use a firm two-handed grip, keep the nose clear, and avoid cutting above shoulder height. Do not force a dull chain or cut with a loose or damaged one.
For tree work, assess lean, defects, wind, targets, and falling hazards. Use a qualified tree-care professional when the work exceeds your training or safe ground-based control. Do not improvise felling cuts if the tree’s fall is uncertain.
After work, engage the brake and shut the saw down before carrying or adjusting it. Let it cool before refueling or servicing, and refuel away from ignition sources. Clean the saw, check the chain and oil, follow the manual’s fuel-storage directions, fit the bar scabbard, and store the saw dry and out of children’s reach.
Frequently asked questions
These quick answers cover the most common MS 290 chain, file, fuel, and setup questions. The installed bar and chain markings remain the final check because replacement parts and configurations can vary.
What size file does a common MS 290 chain use?
A common 3/8-in standard chain uses a 5.2 mm (13/64-in) round file. Confirm the chain model’s filing instructions before sharpening.
What chain pitch does the MS 290 use?
A common setup uses 3/8-in standard pitch. Check the bar and sprocket markings; do not confuse it with 3/8-in low-profile chain.
What chain gauge should I buy?
The common reference is .050 in (1.3 mm). Match the gauge stamped on your bar and make sure the chain pitch and link count also match.
How many drive links do I need?
Common combinations are 60 links for 16 in, 66 for 18 in, and 72 for 20 in. Confirm the exact count on your bar; these are not universal.
What filing angle should I use?
Many standard cross-cut chains use a 30-degree top-plate angle. Follow the chain maker’s instructions, since the correct angle depends on the chain model.
What is the correct fuel mix?
The reference ratio is 50:1 gasoline to 2-cycle oil by volume. That equals 20 mL of oil per liter of gasoline. Use fresh fuel and oil that meet STIHL’s current requirements.
What depth-gauge setting should I use?
The common reference is 0.65 mm (0.026 in). Check the chain model and use its matching depth-gauge tool rather than lowering the gauges by eye.
Can I sharpen a chain while it is on the bar?
Yes, if the saw is shut off and secured, and you follow the manual’s directions. Wear gloves; manage the chain brake as directed so the chain can move for filing.
Why does my chain cut slowly after sharpening?
Check for uneven cutter lengths, an incorrect filing angle, or depth gauges that need attention. Also verify tension, lubrication, and that the chain is not damaged.
Can I use the engine-speed figures to tune the carburetor?
No. The 2,800 rpm idle and 12,500 rpm maximum are reference values. Use the serial-specific service procedure and a tachometer, and never exceed the specified limit.
(This article was written by one of our staff writers, David Hensley. Visit our Meet the Team page.)
