There is nothing—absolutely nothing—more frustrating than gearing up for a day of cutting, getting your PPE on, and then pulling the starter cord only to hear… silence. Or maybe a sputter, a cough, and then silence.
If you are standing in your paddock or backyard in Australia right now staring angrily at a silent chainsaw, you are not alone. It happens to the best of us.
The good news? You probably don't need a mechanic. In 90% of cases, a chainsaw refuses to start because of one of three simple reasons. Before you throw it in the ute and drive to the shop, try these three fixes.
1. The Fuel Has Gone "Stale" (The #1 Culprit)
If your chainsaw has been sitting in the shed since last winter with fuel in the tank, this is almost certainly your problem.
Modern unleaded petrol isn't what it used to be. It has a shelf life. In as little as 30 days, petrol begins to degrade. It loses its "volatile" vapours (the bits that ignite easily) and leaves behind a gummy, sticky residue.
The Australian Factor: In Australia, a lot of our pump fuel (E10) contains Ethanol. Ethanol loves water. If your saw sits for a month, the ethanol in the fuel absorbs moisture from the air. This watery sludge sinks to the bottom of the tank—exactly where your fuel pickup line sits. Your saw is trying to run on water and gum, not fuel.
The Fix:
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Don't just top it up. Adding fresh fuel to bad fuel doesn't work.
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Dump it out. Empty the tank completely into a safe container.
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Refill with fresh Premium. Mix a fresh batch of 2-stroke fuel using 95 or 98 Octane (Premium) petrol. Avoid E10 if you can help it.
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Prime and Pull. It might take a few extra pulls to get the fresh fuel through the lines, but it will often roar to life once the bad stuff is cleared out.
2. You’ve Flooded The Engine (The "Dry Out" Method)
This is the most common "user error," and it happens to pros and beginners alike.
A cold chainsaw needs the choke on to start. But if you pull the cord too many times with the choke on, you dump too much fuel into the engine. The spark plug gets wet and cannot create a spark.
How to tell if it's flooded:
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You can smell raw petrol.
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The engine sounded like it almost started (a "pop"), but you kept pulling with the choke on.
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The starter cord feels harder to pull than usual (this is "hydro-lock"—stop pulling immediately!).
The Fix: Trying to start a flooded saw by holding the throttle open can be dangerous if you lose your grip. The safest, foolproof way to fix this is to physically remove the fuel. You will need your chainsaw tool (scrench).
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Remove the Spark Plug: Take off the top cover and use your scrench to unscrew the spark plug.
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Dry the Plug: If the plug is wet with petrol, wipe it dry with a rag.
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Clear the Chamber: Turn the chainsaw upside down (so the spark plug hole faces the ground) and pull the starter cord 6–10 times. You will see a mist of fuel spray out of the hole—this is the excess fuel leaving the engine.
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Reassemble & Start: Screw the spark plug back in and put the cover on. Set your saw to the "Fast Idle" or "Warm Start" position (usually done by engaging the choke and then immediately clicking it off again). Do not use full choke. Pull the cord, and it should start immediately.
3. It Can't Breathe (The "Aussie Dust" Problem)
An engine needs three things to run: Fuel, Spark, and Air. If you cut Australian hardwoods like Red Gum or Ironbark, you are dealing with a unique problem.
Unlike pine sawdust which is chunky, Aussie hardwood creates a fine, talc-like dust. This dust coats everything. If your air filter is clogged with this fine powder, your engine effectively suffocates. It tries to suck in air but can't, so it sucks in more fuel instead, flooding itself (see point #2).
The Fix:
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Pop the top cover. Most saws have a clip or a single screw to access the air filter.
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Inspect the filter. If it looks like a fuzzy felt pad or is caked in dust, it’s blocked.
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Clean it. Tap it gently against a hard surface or use a soft brush/compressed air (from the inside out) to blow the dust away.
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Check the Spark Plug: While the cover is off, pull the spark plug out. If it’s black and oily, clean it with a wire brush or just buy a new one (they are cheap!).
Still Won't Start?
If you have fresh premium fuel, you’ve cleared the flood, and your air filter is clean, but it still won't start, you might have a deeper issue like a blocked fuel filter (inside the tank) or a spark issue.
Pro Tip for Summer: If you are cutting on a hot Australian day (30°C+), you might get Vapor Lock. The fuel literally boils in the lines. If your saw starts cold but won't restart after you refuel, crack the fuel cap to release the pressure/heat, prime it with cool fuel, and try again.