Stihl 026 Super Problems (Troubleshooting)
Most 026 Super faults can be traced to fuel, spark, air flow, compression, or chain oiling. Start with fresh 50:1 fuel, the air filter, plug, chain brake, and oil delivery before buying parts. Then follow the symptom: test spark, check fuel supply, and assess compression. Stop if the saw races, loses power suddenly, or shows signs of overheating.
A saw that will not start can stall a weekend, and replacing parts at random can lower its resale value without fixing the fault. A clean, working 026 Super is easier to assess and sell than one with an unknown engine problem. I use a simple rule: check what is easy to verify first, and do not tune around a fault that may damage the engine.
The 026 Super is an older, roughly 50 cc professional saw. Details such as carburetor, chain, bar, and service settings can vary by saw and serial number. Check the model markings and the correct manual before ordering parts or setting engine speed.
Start with safety and basic checks
These checks help you rule out simple causes before opening the carburetor or engine. Work outside, away from flames, and let hot parts cool. Wear eye, hearing, hand, leg, and foot protection. Remove the saw from service if its chain brake, throttle return, handles, or chain catcher are damaged.
- Engage the chain brake before starting, and follow the starting steps printed on the saw or in its manual. Keep the bar clear of people and objects.
- Check that the stop switch is in the run position and that the throttle lockout moves freely.
- Confirm the chain is fitted in the correct direction and is not too tight. The pitch, gauge, and drive-link count must match the bar and drive sprocket.
- Check the air filter, fuel level, visible fuel lines, and bar-oil level.
Do not run straight gasoline in this two-stroke saw. With suitable STIHL two-stroke oil, use the 50:1 mix specified in the supplied guidance: 1 litre of gasoline to 20 mL of oil. Follow the applicable manual and oil instructions, and use fresh fuel.
Diagnose a no-start in order
A no-start means the engine does not fire and keep running, or does not fire at all. The main checks are fuel, spark, and compression. Test them in that order after confirming the controls and start procedure, because a flooded engine or stale fuel can mimic a failed part.
Check fuel and flooding
Use fresh, correctly mixed fuel. If fuel has been stored for a long time, replace it rather than relying on it for diagnosis. Inspect the fuel filter and lines for visible damage, loose connections, or signs of blockage; a restricted tank vent can also limit fuel flow.
If the plug is wet after repeated start attempts, the engine may be flooded. Stop pulling the starter and follow the manual’s flooded-engine procedure. Avoid repeated full-choke pulls; they can add more fuel without helping the engine start.
Check spark safely
A spark tester is the safer way to check ignition. Connect it as directed by the tester maker, keep fuel vapour away, and follow the saw’s manual. A plug that looks dirty or wet may need cleaning or replacement, but appearance alone does not prove that the ignition system is working.
Use the plug type and gap specified for the saw’s serial-specific manual. If the tester shows no spark, inspect the stop-switch wiring and plug connection before suspecting the ignition module. Do not buy a coil until the wiring and test setup are checked.
Check compression and signs of engine damage
Compression is the pressure made as the piston moves in the cylinder. A compression gauge can help identify a major loss, but use a suitable gauge and interpret the result with the correct service information. Pulling resistance is only a rough clue, not a measured diagnosis.
If the saw has sudden power loss, a metal sound, or a piston that appears scored through the exhaust opening, stop. Fuel starvation, wrong mix, or an air leak can cause overheating and seizure. Do not keep trying to start it until the cause is found.
If it starts, then stalls, races, or bogs
A saw that starts and dies, runs unevenly, or loses power under load may have a fuel, air-flow, exhaust, ignition, or air-leak problem. Check simple restrictions first. If the idle races or will not settle, stop rather than trying to hide the fault with carburetor adjustments.
| Symptom | First checks | Next diagnostic step |
|---|---|---|
| Starts, then dies | Fresh fuel, filter, fuel line, tank vent | Have fuel delivery and carburetor checked |
| Bogs when cutting | Air filter, fuel supply, muffler screen | Check ignition and carburetor operation |
| Races at idle | Throttle return, intake parts, fuel lines | Stop and have intake and crankcase seals tested |
| Chain moves at idle | Idle speed and clutch condition | Stop use until repaired |
| Sudden power loss | Fuel supply, overheating, engine condition | Stop immediately; inspect for seizure damage |
Clean the air filter as its maker directs. Check the muffler and spark-arresting screen for blockage, if fitted. A blocked screen can reduce power, but so can a dull chain or a bar pinched in the cut, so note whether the engine also runs poorly with no cutting load.
A crankcase air leak lets unmetered air into the engine. That can make the fuel mixture too lean, meaning there is too much air for the fuel. A technician can use pressure and vacuum tests to check the crankcase and intake seals. Do not richen the carburetor to compensate for a suspected leak.
Case pattern: the saw runs briefly, then quits
When I narrow down this symptom, I first ask whether the engine dies at idle, under throttle, or only after it warms up. That timing helps choose the next check; it does not identify a failed part by itself. I verify fresh fuel and filter condition, then inspect the vent, air filter, and exhaust screen before moving to specialized tests.
Check cutting performance and chain oiling
A saw that runs but cuts poorly may have a dull or incorrectly fitted chain, a worn bar or sprocket, or an engine fault. A chain that does not receive oil can overheat and wear quickly. Keep the chain brake, throttle lockout, and stop switch working before returning the saw to service.
The 026 Super is roughly 50 cc, but bar fit depends on the specific saw and approved components. A 16- to 18-inch bar is a practical general-purpose match; longer bars require approval for that saw and the cutting conditions. Check the bar and chain markings. Common configurations vary, so do not assume a pitch, gauge, or drive-link count.
To check oil delivery, fill the oil tank with suitable bar-and-chain oil and follow the manual’s test method. If the manual permits, run the saw briefly with the bar aimed toward clean ground or cardboard to look for oil spray. Keep the chain clear of people and surfaces; do not touch a moving chain. If oil does not appear, stop and clean the bar groove and oil passages. Have the pump or drive checked if the fault remains.
If cutting is slow, inspect cutter sharpness and depth gauges, also called rakers. These limit how deeply each cutter bites. File and set them to the chain maker’s specification with the correct tools. Do not use one assumed setting for every chain. Never force a dull chain through wood or continue with a loose, damaged, or poorly oiled chain.
Choose the next step without guessing at parts
A part should be replaced when a test or inspection points to it, not just because it is a common failure. Before ordering, match the saw’s model and serial information, carburetor identification, and the bar and chain markings. Carburetor and engine-speed settings can vary, so use the correct manual and a tachometer rather than a generic online RPM value.
- If there is no spark, check the tester connection, plug, and stop-switch wiring before replacing ignition parts.
- If fuel is stale or the filter is visibly damaged, correct that first, then retest.
- If it races at idle or tuning will not stay stable, stop and request pressure and vacuum testing for leaks.
- If the chain will not oil, clean the groove and passages, then seek service if delivery remains poor.
One useful diagnostic pattern is to change one condition at a time. For example, a fresh fuel mix and clean filter are a sensible first test for a saw that has sat unused. If it still stalls, record when it dies and what you have checked. That prevents a string of unverified parts from hiding the original fault.
Return the saw to service and protect its value
A safe repair includes more than a running engine. Inspect the brake, throttle return, handles, catcher, fasteners, bar, chain, and sprocket. Clean cooling fins and the starter intake, and remove debris around the muffler. If any safety part is cracked or unreliable, do not operate the saw.
After service, confirm it idles without chain movement, responds to throttle without racing, and oils the chain. Use the correct manual for any idle or maximum-speed setting. Store the saw clean and secure, with the chain covered; for long storage, follow the manual’s fuel-system instructions. Keep notes of verified repairs and matching parts. Clear records can help a future buyer judge the saw’s condition.
Frequently asked questions
Why will my Stihl 026 Super not start?
Check the start procedure, fresh 50:1 fuel, plug condition, and spark with a tester. If those checks pass, assess compression and fuel delivery before replacing parts.
What fuel mix does an 026 Super use?
The supplied guidance specifies 50:1 with suitable STIHL two-stroke oil: 20 mL of oil per 1 litre of gasoline. Follow the manual and oil instructions for your saw.
Why does my 026 Super start and then die?
Possible causes include stale fuel, a restricted filter or vent, a dirty air filter, or a blocked exhaust screen. If basic checks do not help, have the carburetor and seals tested.
Why does my saw race at idle?
A high or unstable idle can point to a throttle, fuel, intake, or air-leak problem. Stop using it and do not try to correct a suspected air leak by adjusting the carburetor.
Why does the chain move while the saw idles?
Stop the saw. A chain moving at idle may mean the idle speed or clutch needs attention. Do not operate until the cause is repaired.
How do I check whether the chain is getting oil?
Follow the manual’s test method. If permitted, briefly check for oil spray over a clear surface while keeping the chain away from people. Stop and clean the bar groove and oil passages if delivery is poor.
What bar length fits an 026 Super?
A 16- to 18-inch bar is a practical general-purpose match, but the approved setup depends on the saw and components. Confirm bar, chain, and sprocket compatibility before fitting parts.
Should I adjust the carburetor if the saw bogs?
Not as a first step. Check fuel, air filter, exhaust screen, and fuel delivery. If the saw races or tuning will not stabilize, investigate for leaks before adjustment.
Can I keep running the saw after sudden power loss?
No. Stop and check for fuel starvation or overheating. Continuing to run a lean or damaged engine can cause severe damage.
What should I check before using the saw after storage?
Use fresh, correctly mixed fuel, inspect the fuel lines and filter, check chain fit and tension, test the safety controls, and confirm bar-oil delivery.
(This article was written by one of our staff writers, Robert Callahan. Visit our Meet the Team page.)
