How Does the Stihl MS 251 Perform When Removing Ash Trees Infested by Emerald Ash Borer?
The Stihl MS 251 is a mid-range chainsaw that many arborists and homeowners rely on for removing ash trees damaged by the Emerald Ash Borer (EAB). With a 45.4 cc engine and a power output of 3.2 kW, it provides sufficient torque for cutting through the dense, brittle wood of infested ash trees. The saw’s 18-inch bar is ideal for most ash trunks up to 24 inches in diameter, though larger trees may require additional cuts. For typical EAB removal tasks, the MS 251 offers a good balance of power and maneuverability, especially when working in tight residential spaces where ash trees often stand near structures.
Ash wood affected by EAB becomes structurally compromised, often with vertical cracks and hollowed interiors. The Stihl MS 251’s anti-vibration system helps reduce operator fatigue during prolonged cuts, which is essential when dealing with these unpredictable trees. The saw’s Quickstop chain brake provides a critical safety feature when limbs or tops unexpectedly fail. For Professional vs DIY Tree Removal: Is It Worth It with Stihl MS 251?, this saw fits well into both categories, though professional arborists may prefer a larger model for continuous heavy-duty use.
What Is the Best Technique for Felling an Ash Tree with the Stihl MS 251?
Felling an ash tree infested by EAB requires careful planning due to the wood’s brittleness. Start by assessing the tree for signs of decay, such as bark peeling, D-shaped exit holes, and woodpecker activity. Use the Stihl MS 251 to make a conventional notch cut at the intended fall direction, cutting to about one-third of the trunk diameter. Then, make a horizontal back cut slightly above the notch hinge. The saw’s chain speed of 13.8 m/s provides clean cuts even in dry, brittle ash wood.
For trees with significant decay, consider using a rope-assist method to control the fall direction. The Stihl MS 251’s lightweight design (5.6 kg without bar and chain) allows for easy one-handed operation when pulling the ropes, though always maintain both hands on the saw during cuts. Avoid cutting through completely if the tree is hollow; instead, leave a thick hinge to prevent premature splitting. For emergency situations after windstorms, review Stihl MS 251 Emergency Tree Removal After Heavy Wind Damage: Tips and Techniques for additional safety protocols.
How to Safely Section and Remove Ash Tree Limbs with EAB Damage?
Once the ash tree is felled, the next step is limb removal and sectioning for disposal. EAB-damaged limbs often have weak attachment points and can snap unexpectedly. Use the Stihl MS 251 to make relief cuts on the underside of limbs before cutting from the top to prevent bark tear. The saw’s 16-inch bar is sufficient for most limbs up to 18 inches thick, though for larger limbs, make multiple cuts.
When working with overhanging branches, always maintain a stable footing and clear the area below. The Stihl MS 251’s decompression valve and Easy2Start system reduce starting effort, which is helpful when moving between multiple limb cuts. For logs intended for firewood, cross-cut them to 16- to 18-inch lengths. Ash wood burns well even when infested, but avoid storing infected wood near healthy trees. Consider wearing recommended safety gear; see Stihl MS 251 Safety Gear for Chainsaw Operators for a complete list.
What Are the Key Specifications of the Stihl MS 251 for Ash Tree Removal?
Understanding the technical specifications of the Stihl MS 251 helps operators match it to the specific demands of EAB ash tree removal. The table below compares its key specs with typical ash tree removal needs.
| Specification | Stihl MS 251 Value | Relevance to EAB Ash Removal |
|---|---|---|
| Engine displacement | 45.4 cc | Sufficient for cutting up to 24-inch ash trunks |
| Power output | 3.2 kW (4.3 hp) | Provides torque for dense, brittle ash wood |
| Weight (without bar/chain) | 5.6 kg (12.3 lbs) | Light enough for overhead limb removal |
| Recommended bar length | 18 inches (45 cm) | Ideal for most residential ash trees |
| Chain pitch | .325 inch | Matches standard ash cutting speeds |
| Chain oil capacity | 0.3 L | Requires frequent refills for heavy cutting |
| Fuel tank capacity | 0.5 L | Runs approx. 45 minutes under load |
| Oilomatic chain type | 3/8″ PM3 | Reduces friction during cutting |
| Average retail price (UK) | £450–£550 | Cost-effective for DIY vs. pro use |
The MS 251’s chain speed of 13.8 m/s (45 ft/s) enables clean cuts through ash wood, reducing the risk of binding. Its anti-vibration system reduces hand fatigue during extended cutting sessions, which is common when removing multiple infected trees. For more details on post-removal processing, see Stihl MS 251 for Stump Grinding After Tree Removal: Techniques and Safety.
How to Dispose of Ash Tree Debris Infested with Emerald Ash Borer?
Proper disposal of EAB-infested wood is critical to prevent the spread of the borer to healthy ash trees. After cutting, chip, burn, or bury the wood to kill larvae. The Stihl MS 251 can be used to cut logs into manageable sections for transport to a disposal site. Check local quarantine regulations; many areas require infested wood to be processed on-site or at approved facilities.
When chipping ash branches, ensure the saw is properly maintained with a sharp chain to avoid tearing the wood, which can leave larger pieces. The Stihl MS 251’s side-access chain tensioning makes it easy to adjust the chain quickly between cuts. For firewood, split the logs to speed drying and kill any remaining larvae. Stack the wood away from healthy trees and cover it with clear plastic in summer months for at least a year. Using the Stihl MS 251 for this task means checking the chain tension after each tank of fuel due to the heat generated by cutting dry wood.
What Do Owners Say About the Stihl MS 251 for Ash Tree Removal?
Owners of the Stihl MS 251 generally praise its reliability for removing ash trees affected by EAB. Many report that the saw starts easily even in cold weather, which is common for early spring removals when adult borers are active. The power-to-weight ratio is often highlighted as a major advantage, allowing for hours of cutting without shoulder or back strain.
A carpenter from Yorkshire noted, “I’ve used this saw to take down six infected ash trees on my property. The 18-inch bar cuts through 20-inch trunks in one pass. The anti-vibration is a lifesaver when cutting 30 logs in a row.” Another user in Surrey appreciated the fuel efficiency, stating, “I can cut a full ash tree into firewood on just two tanks of fuel. That’s about 90 minutes of continuous work.” However, some owners mention that the chain oil reservoir is small, requiring refills several times per day for heavy usage. For storm-damaged ash trees, owners recommend the extra precautions covered in Stihl MS 251: Essential Safety Gear for Post-Storm Cleanup.
Frequently Asked Questions
Q1: Can the Stihl MS 251 handle large ash trees with multiple trunks?
A1: Yes, the MS 251 can handle multi-stemmed ash trees if each stem is under 24 inches in diameter. For larger stems, make relief cuts or use a larger saw. Always assess the tree split potential, as EAB damage weakens crotches. Use notch cuts and back cuts carefully to avoid bar pinching.
Q2: How often should I sharpen the chain on the Stihl MS 251 for ash wood?
A2: For dry, brittle ash wood, sharpen the chain every 2–3 tanks of fuel. For damp or green wood, sharpen every 4–5 tanks. Use a round file matching the chain pitch (.325 inch) and maintain a 30° filing angle. Dull chains increase kickback risk, especially in hard ash.
Q3: Is it safe to use the Stihl MS 251 for felling partially hollow ash trees?
A3: It can be safe if you assess the tree first. Hollow ash trees may have thin shells and can split unpredictably. Make a shallow notch cut and a conservative back cut. Use wedges to prevent bar pinching. For severe hollowing, consult a professional before cutting.
Q4: What is the cost of a Stihl MS 251 in the UK as of 2025?
A4: The recommended retail price for a new Stihl MS 251 (with 18-inch bar) ranges from £450 to £550, depending on the dealer and included accessories (e.g., chain, bar cover, carrying case). Used models cost between £250 and £350.
Q5: Can I use the Stihl MS 251 for cutting EAB-infested wood into firewood?
A5: Absolutely. The MS 251 excels at cross-cutting ash logs into 16- to 18-inch firewood lengths. Ensure the wood is dry to reduce chain wear. Split the wood soon after cutting to allow rapid drying and kill any borers. Avoid storing firewood near healthy ash trees.
Q6: How does the Stihl MS 251 compare to electric chainsaws for ash removal?
A6: The MS 251 provides greater torque and portability than most corded or battery electric saws for heavy-duty ash removal. It is not limited by battery runtime or cord length. However, it requires fuel mixing and more maintenance. For small limbs (under 6 inches), an electric saw may suffice.
