Stihl 039 Chainsaw Features (Owner’s Guide)
The STIHL 039 is an older, 64.1 cc two-stroke chainsaw built for substantial cutting work. Its key features include a chain brake and safety controls, but the exact bar, chain, and sprocket setup can vary. Before using one, verify the saw’s condition and configuration, follow its manual, and use the correct fuel mix and protective gear.
A chainsaw can look ready for work while hiding a small mismatch: the chain may fit the bar but not the sprocket. That is why, when I assess an older 039, I treat its installed parts and condition as carefully as its model badge. This guide covers its main features, setup, cutting, care, and what to verify before you put it to work.
STIHL 039 features and specifications
The 039 is a substantial older saw with a 64.1 cm³, air-cooled, two-cycle engine. Its exact equipment can vary with the saw’s version and later repairs. Think of its model name as a starting point, not proof that every used saw still has its original parts or is safe to run.
| Feature | What to know |
|---|---|
| Engine | 64.1 cm³, two-cycle, air-cooled |
| Fuel | 50:1 gasoline-to-oil by volume when using STIHL two-stroke oil; follow the manual for other oil |
| Bar and chain | Match pitch, gauge, and drive-link count to the bar and drive sprocket |
| Common chain pitch | 3/8 inch is common, but check the installed parts |
| Bar length | A 16–20 inch bar is a practical general-purpose range only when approved for that saw’s configuration |
| Safety equipment | Check the chain brake, throttle lockout, chain catcher, handles, and other fitted controls |
The 039 is often described as a professional-grade saw. That label does not tell you whether a particular used example is worn, modified, or suitable for a task. A sound saw with matched parts matters more than a badge or a seller’s description.
Look for the model and serial number on the saw, then compare its parts with the correct manual for its version. A serial number alone may not give you a reliable public decoding of build date or origin. If those details matter, ask a STIHL dealer or STIHL support to check the full number.
Equipment setup and safety preparation
A safe setup means checking the saw as a working system, not just confirming that it starts. The engine, sprocket, bar, chain, chain brake, fuel, and oil all affect how it runs. Use the manual for the saw’s version, since used 039s may have different bars or replacement parts.
Start with the chain fit. Pitch is the distance standard used to match chain links to the sprocket and bar nose. Gauge is the thickness of the drive links that sit in the bar groove. Drive-link count is the number of links that travel around the bar. All three must match the markings on the bar and the sprocket.
A chain may appear close enough to fit yet still be wrong. Do not guess from bar length or from a chain sold for another saw. If the markings are worn or unclear, have a dealer identify the parts before cutting.
Before starting
- Wear a helmet, eye and hearing protection, chainsaw-protective legwear, gloves, and suitable boots.
- Inspect the chain brake, throttle lockout, chain catcher, handles, bar, chain, and fasteners. Do not use the saw if a safety part is missing or damaged.
- Check chain tension using the manual’s procedure. A loose chain can come off; an overly tight chain can add wear.
- Fill with the correct fuel mix and approved bar-and-chain oil. Never use straight gasoline.
- Check footing, overhead hazards, nearby people and structures, the tree or limb’s lean, and escape routes before cutting.
Start the saw only as the manual directs, on stable ground, with the chain clear of the ground and nearby objects. Warm it briefly and confirm oil delivery as directed by the manual before cutting. If you cannot confirm lubrication, stop and find the cause rather than running the chain dry.
Field cutting and landscaping operation
The 039’s displacement makes it capable of demanding cutting work, but that does not make every bar length or task suitable. A longer bar adds load and should be used only if approved for the exact saw, sprocket, brake, and chain setup. Bar length alone does not define safe cutting capacity.
The bar nose is the rounded tip of the guide bar. Contact with its upper quadrant can cause rotational kickback, a sudden movement that throws the saw back toward the operator. Keep that part of the bar away from branches, logs, and the ground. Hold the saw with both hands, and do not cut above shoulder height. A chain brake can reduce risk; it cannot make nose contact safe.
Plan each cut around the wood’s weight and tension. A limb may shift, pinch the bar, or spring as its support changes. If the wood moves unexpectedly or the chain binds, stop and reassess. Do not force a dull, damaged, or mismatched chain through the cut; forcing it can increase heat, binding, and risk.
| Situation | Practical approach |
|---|---|
| Firewood on stable supports | Confirm the wood cannot roll or shift; keep the bar nose clear and use a matched chain |
| Pruning or limb removal | Assess tension and overhead hazards; do not cut above shoulder height |
| Felling a tree | Use trained felling methods, an adequate hinge, and a clear escape route; get qualified help if unsure |
| Chain binds or saw behaves oddly | Stop, switch off, and inspect; do not pull or twist the saw free while it is running |
These examples are setup scenarios, not reports of specific saws or approved combinations. For felling and other high-risk work, training matters. Follow applicable safety rules, including relevant ANSI Z133 and OSHA requirements where they apply.
Regular care helps preserve cutting performance and can reveal problems before they become failures. Clean and inspect the saw as the manual directs. For engine tuning, use the exact manual for the saw’s version and the stated tachometer procedure; do not rely on an unverified internet RPM figure.
A sharp chain cuts with less effort than a dull one. When sharpening, use the file size and angles specified for that chain. Depth gauges control how much wood each cutter takes. A setting of 0.65 mm (0.025 inch) is common for standard 3/8-inch chain, but it is not universal. Check the chain maker’s instructions before filing depth gauges.
After sharpening, inspect the cutters and links for damage. Replace a chain that is cracked, badly worn, or otherwise unsafe. Check the bar groove and sprocket area for packed debris, and inspect the bar and sprocket for wear. If the saw cuts poorly despite a sharp chain, investigate the setup and condition rather than increasing engine speed.
Do not adjust the carburetor by ear or use a generic wide-open-throttle (WOT) or idle speed as a target. Incorrect tuning can damage the engine and create unsafe operation. If you lack the right manual, tachometer, or experience, have a qualified STIHL dealer handle the adjustment.
Storage and seasonal care
Good storage starts with a clean, inspected saw and a cool engine. After use, switch off the saw, allow it to cool, and clean debris from the bar groove, sprocket area, and air-intake areas as the manual instructs. Check chain tension and damage before putting the saw away.
Refuel only after the engine has cooled. For longer storage, follow the fuel and preservation directions in the manual for the specific version and fuel used. Do not assume that every fuel-storage method suits every machine. Keep the saw out of reach of children, with the chain protected and the machine secured.
Before returning it to service, inspect the safety parts, chain fit, tension, and oil supply again. A saw that sat unused may still have stale fuel, a stuck control, or a lubrication problem. Start it only after resolving concerns, and follow the manual’s starting procedure.
Frequently asked questions
How big is the STIHL 039 engine?
It has a 64.1 cm³, air-cooled, two-cycle engine.
What fuel mix does the 039 use?
Use a 50:1 gasoline-to-oil mix by volume when using STIHL two-stroke oil. Follow the manual for the oil actually used, and never run straight gasoline.
What bar length is right for an 039?
A 16–20 inch bar is a practical general-purpose range only when the bar and chain are approved for the specific saw and setup. A longer bar increases load and is not automatically safe because it fits.
Does every 039 use the same chain?
No. Match chain pitch, gauge, and drive-link count to the bar and drive sprocket. Check the installed bar’s markings rather than relying on the model name.
Is 3/8-inch chain correct for the 039?
It is common, but that alone does not confirm a correct fit. Verify pitch, gauge, and drive-link count for the actual bar and sprocket.
What fuel should I avoid?
Do not use straight gasoline or an incorrect oil mix. Poor lubrication can cause serious engine damage, including piston or cylinder damage.
How do I know if the chain is sharp?
A sharp chain cuts cleanly when used correctly. If it is dull, damaged, or mismatched, stop and sharpen or replace it according to the chain maker’s directions.
Can I use 0.025-inch depth-gauge settings?
That setting is common for standard 3/8-inch chain, but it is not universal. Follow the instructions for the specific chain.
How can I decode an 039 serial number?
Do not assume the number reveals the saw’s age or origin through a universal public code. Record the full serial number and ask a STIHL dealer or STIHL support to check it.
What should I do if the chain oil is not reaching the bar?
Stop cutting. Check the oil supply and saw as the manual directs, and have a dealer inspect it if delivery remains uncertain.
Is the 039 a professional saw?
It is often described as professional-grade, but that label does not establish the condition or suitability of a used saw. Inspect its parts, safety features, and service history before use.
The most reliable way to judge an 039 is to identify its exact configuration, confirm the safety systems work, and follow the manual for that version. If the bar, chain, or service history is uncertain, have a qualified dealer check it before you cut.
(This article was written by one of our staff writers, Elliott Fowler. Visit our Meet the Team page.)
