Starting a Flooded Chainsaw – A Quick Guide
One of my youngest memories is being with my father in an orchard out of the city cutting trees for firewood.When we were done, the car, stacked up with firewood, wouldn't start.
We had to wait for what felt like forever for my mum to turn up to take me home while Dad tended to the car.
And what does that have to do with starting flooded chainsaw engines?
Nothing, except to say my dad was pretty handy with a chainsaw. He had a green Poulan and as a kid, it just seemed the coolest thing in the world.
Anyways, enough of this chit chat – here are some:
Tips on Starting a Flooded Chainsaw
Before we get into it, make sure you have fresh petrol in your engine.
If you've got an old mixture of oil and gas that's older than a month, it will be harder for your engine to start.
We suggest you drain and add fresh petrol to ensure a good start.
If you have tried several times unsuccessfully to start your unit, it is most likely flooded, especially so if you can smell gas.
Flooded means there is excessive fuel pumped into the engine, which has displaced the vital ingredient of oxygen for starting.
Do not prime the engine again as you will add to the problem!
There are two ways you can try to clear the unit of the excess fuel and get it chopping wood.
The first is the easiest and most common method. Let your chainsaw sit for 15–20 minutes to allow the fuel to evaporate from the engine, and then repeat the starting instructions.
This method will work best with a mildly flooded engine. The same principles apply to lawnmowers and weed whackers.
The More Hands-On Method to Start a Flooded Chainsaw:
- Have the chain brake engaged
- Turn the choke off
- Activate the fast idle (usually by engaging the throttle lock or pulling the choke and pushing it back in)
- Ensure the on/off switch is on
- Place the saw firmly on the ground, hold it steady, and pull the starter rope with short, sharp motions
If the engine doesn't fire after 15 pulls, the spark plug may be 'wet fouled'. In this case, remove the spark plug and inspect it for wet, oily deposits.
While the plug is out, turn the saw upside down and pull the starter a few times to eject any excess fuel through the spark plug hole.
Use a lighter or torch (carefully and away from fuel!) to gently dry the spark plug tip, or replace it if it’s old or damaged. A good spark plug makes a big difference on cold starts.
Once the plug is re-installed, prime the carburetor. If your chainsaw has a primer bulb, press it 3–6 times until you see fuel moving through the line.
Now start your machine using the normal procedure — choke on, pull to pop, then choke off and fire it up.
Why Chainsaws Flood So Easily
Chainsaw carburetors are finicky. A rich air-fuel mix helps cold-start a 2-stroke engine, but too much fuel and not enough spark or oxygen will choke it out. This is especially common when:
- You're unfamiliar with the saw and over-choke it
- You're doing multiple false starts
- Ambient temperatures are cold, thickening the fuel
- The air filter is dirty or saturated with oil
Always follow your chainsaw’s specific startup sequence. Each model is a little different. Some have auto-choke. Others need a specific throttle pull to engage fast idle. Reading the manual — even just once — pays off.
How to Prevent Chainsaw Flooding
- Always use fresh fuel (ideally with a stabilizer like Sta-Bil if storing)
- Don’t pump the primer bulb too many times
- Know when to use full vs half choke — it’s a timing game
- Check for clean air filter and strong spark
- Pull the cord briskly — slow or hesitant pulls won’t ignite properly
Here’s a Great Video Tutorial on Starting Your Saw:
Extra for Chainsaw Experts:
- How to sharpen a chainsaw – Learn the right angles, file sizes, and techniques to keep your chain cutting clean and fast.
- How to reduce the chance of chainsaw kickbacks – Understand kickback zones, safety features, and handling tips to stay in control.
- How to make sharp, safe cuts with a chainsaw – A guide to body positioning, saw movement, and cut planning for accuracy and safety.
- The 4 basic rules of chain maintenance – Covers cleaning, tensioning, lubrication, and inspection to extend chain life and boost performance.