Stihl MS 250 18 in. 45.4 cc Gas Chainsaw (5 Pro Tips)
The STIHL MS 250’s 45.4 cm³ engine and common 18-inch setup can suit occasional limbing and bucking, if the bar and chain match the saw and the work fits your skill. It is not a shortcut to safe cutting: check the manual, use proper protective gear, and stop if the wood or saw behaves unpredictably.
If you are comparing saws in the $300–$700 range, the useful question is not whether this model has an 18-inch bar. It is whether its setup and capacity fit the wood you plan to cut, without making the saw hard to control or maintain. Bar length alone does not tell you which chain fits.
I use a simple buying test: match the saw to your usual cuts, then confirm the exact parts and safe operating steps in the model’s manual. The MS 250 may make sense for occasional property work. For long sessions in large, hard wood, a longer bar is not automatically an upgrade; it adds load and raises kickback exposure.
Is the MS 250 with an 18-inch bar a good fit?
The MS 250 is a gas-powered saw with a 45.4 cm³ engine. An 18-inch bar is a common configuration, but the right choice depends on the wood, the operator, and the exact bar-and-chain combination. Check the saw’s manual and component markings before buying or fitting parts.
For occasional limbing and bucking, this setup can be practical when the cuts are within your training and ability. “Bucking” means cutting a felled trunk or branch into shorter sections. “Limbing” means removing branches from a felled tree. Neither task is safe simply because the saw can reach the wood.
The trade-off is that a longer bar can reach farther into a cut, but also puts more cutting system in contact with wood. Larger logs and sustained cutting in hard wood increase the load on the saw and can make control more demanding. A shorter approved bar may be easier to manage for smaller work.
| Your work | What to consider | Fit for this setup |
|---|---|---|
| Occasional limbing and smaller bucking cuts | Stable footing, sharp chain, wood within your skill | Often a reasonable match |
| Frequent long sessions in large, hard wood | Heat, cutting load, fatigue, and bar length | Compare a saw designed for heavier use |
| Uncertain chain or bar details | Pitch, gauge, drive-link count, and manual listing | Do not fit parts until confirmed |
| Felling a leaning, damaged, or large tree | Tree hazards and ability to control the fall | Stop and use a qualified tree professional |
A 45.4 cm³ rating describes engine displacement, not a promise that the saw will cut every log quickly. Your decision should rest on the work, not the engine number alone. If most of your tasks are short and occasional, assess this model on that basis.
Five pro tips for setup and safe use
These five tips cover the steps that matter most before, during, and after a cut. They do not replace hands-on training or the STIHL manual. Keep the saw within the work you can control, and stop whenever equipment, footing, or wood conditions create doubt.
1. Inspect the saw before fueling
Check that the chain brake engages, the throttle trigger and interlock work, and the chain catcher is present and undamaged. Look over the bar, chain, fasteners, and drive links. Confirm chain tension using the method in the manual; stop the engine before making adjustments.
Wear a helmet with eye and face protection, hearing protection, chainsaw chaps, gloves, and protective footwear. Before cutting, look for overhead hazards, unstable ground, wind, and the tree’s lean. For felling, plan an escape route and keep others outside the work area. Do not begin if you cannot plan the work safely.
2. Match the chain, fuel, and start procedure
An 18-inch bar does not identify every chain detail. A common MS 250 18-inch setup uses 3/8-inch Picco pitch, 0.050-inch (1.3 mm) gauge, and 62 drive links. Configurations vary, so read the markings on your bar and chain and check the saw’s manual before fitting parts. Pitch and gauge must match the bar and drive sprocket; drive-link count must match the bar.
Use fresh gasoline mixed 50:1 with STIHL two-stroke engine oil. Do not use straight gasoline or guess at the ratio. Start the saw on stable ground, with the chain brake engaged and the bar clear of people and objects. Follow the manual’s cold- or warm-start steps. Do not drop-start the saw. Disengage the choke as directed once the engine fires, then check that the chain stops at idle.
3. Keep control through the cut
Use two hands on the handles and keep stable footing. Cut below shoulder height, and do not operate overhead or while climbing unless you are trained and equipped for that work. Keep your body clear of the cutting path and avoid using the guide-bar nose.
The upper quadrant near the bar tip can cause rapid rotational kickback if it contacts wood or another object. A firm grip helps, but it does not prevent every kickback. Keep the chain sharp and let it cut at its own rate. Pushing harder is not a safe fix for a dull chain.
4. Plan for pinching, tension, and tree hazards
Before bucking, consider how the piece is supported and where its weight will move as the cut opens. Wood under compression can close on the bar; wood under tension can shift or spring when released. Plan cuts to avoid trapping the bar. If it becomes pinched, stop and secure the work before correcting the cause. Never force a trapped bar free with the running saw.
Felling requires more than making a notch. It calls for a planned direction of fall and an intact hinge suited to the tree. Do not improvise on trees with significant lean, defects, or a risk of splitting upward, known as a barber chair. If you cannot control the hazards, stop and contact a qualified tree professional. Follow applicable worksite rules and training guidance, including ANSI Z133 and OSHA requirements where they apply.
5. Maintain the cutting system as a set
After use, stop the engine and engage the chain brake before cleaning or adjusting the saw. Clear debris from the guide-bar groove and oil hole, then inspect the bar rails, chain, and sprocket. Check chain tension and rotate the bar periodically if the manual allows it.
Sharpen with the file size and angle specified for the installed chain. Set depth gauges, also called rakers, to that chain maker’s specification; do not file them to a generic clearance. Use approved bar-and-chain oil and check oil delivery by the manual’s procedure. If the chain moves at idle, the saw stalls, or the engine runs abnormally, stop work and arrange service instead of guessing at carburetor settings.
Setup scenarios: check the details before cutting
These examples are illustrative setup checks, not reports of individual field tests. They show how the same saw can suit one task and be a poor choice for another. Use the markings on your own bar and chain, plus the manual, to confirm the right configuration before work begins.
| Scenario | Check before use | Safer next step |
|---|---|---|
| You are replacing a worn chain on an 18-inch bar | Read pitch, gauge, and drive-link count from the bar and chain | Buy a chain matching all three and the drive sprocket |
| You inherited a saw with unknown parts | Check component markings and the model-specific manual | Have a dealer or qualified service shop confirm fit |
| You plan occasional limbing and bucking | Assess wood size, footing, chain sharpness, and your skill | Proceed only with controlled cuts and a clear work area |
| The bar binds or the engine loses power | Check for pinching, dull or damaged parts, and abnormal running | Stop; resolve the cause or seek service |
A common combination is useful as a starting point, not a universal parts order. If markings are missing or conflict with the manual, do not assume that a chain described online as “18-inch” will fit. Ask a STIHL dealer or qualified saw shop to identify the correct parts.
Maintenance, storage, and signs to stop
Basic care helps the saw remain ready, but it cannot make a worn or damaged cutting system safe. Clean and inspect the equipment after use, store fuel according to the manual and fuel-product instructions, and investigate poor running before the next job. If the saw overheats or loses power, stop it rather than cutting on.
Use fresh, correctly mixed 50:1 fuel. Stale or incorrectly mixed fuel can contribute to poor running and engine damage. If the saw runs abnormally, overheats, or loses power, shut it down. Continuing to run it may cause severe damage. If fresh fuel does not resolve the problem, have the fuel system and engine checked.
For storage, follow the manual and fuel product’s directions for draining or stabilizing fuel. Keep the saw cool, dry, and away from ignition sources. Clean the powerhead and cutting equipment, protect the bar and chain, and inspect everything before returning the saw to service.
Frequently asked questions
These quick answers address common buying and setup questions about the MS 250 with an 18-inch bar. Check the markings on your specific parts and consult the model-specific manual when details differ. For damage, unusual running, or uncertain compatibility, ask a qualified service provider.
Is an 18-inch bar suitable for the MS 250?
It is a common configuration, but confirm that the bar is approved for your saw and that the chain and sprocket match it.
What chain fits an 18-inch MS 250 bar?
A common setup is 3/8-inch Picco pitch, 0.050-inch (1.3 mm) gauge, and 62 drive links. Check your actual bar markings and the manual, since configurations vary.
What fuel mix does the MS 250 use?
Use a 50:1 mix of gasoline and STIHL two-stroke engine oil, following the manual and fuel-product instructions.
Can I use a longer bar?
Do not assume a longer bar is approved or a better choice. Confirm compatibility in the manual; longer bars and sustained cuts in large, hard wood increase load and kickback exposure.
What should idle speed be?
The approximate idle speed is 2,800 rpm. Use the model-specific manual for adjustment details and service limits. If the chain moves at idle, stop work and have the saw checked.
How should I set the chain depth gauges?
Follow the exact specification for the installed chain and use the right depth-gauge tool. Do not use a generic filing clearance.
What should I do if the bar gets pinched?
Stop the saw, secure the work, and correct the cause before continuing. Do not force the bar free with the running saw.
Can I keep cutting if the saw loses power or overheats?
No. Stop the engine and let a qualified service provider check it if the problem persists. Running it while it behaves abnormally may cause severe damage.
For a cost-conscious buyer, the MS 250 is worth considering when its approved 18-inch setup matches occasional, controlled work and you are prepared to maintain it correctly. Confirm the parts and manual first. If the job involves difficult trees, long heavy cuts, or conditions beyond your training, choose a safer plan rather than trying to make this saw cover every task.
(This article was written by one of our staff writers, Marcus Thorne. Visit our Meet the Team page.)
