Preparing your lawn mower for off-season storage

Across most of Australia, lawn mowing happens year-round in warmer regions and tapers off as the cooler months settle over Melbourne, Hobart, and the ACT. Even in subtropical Brisbane, growth slows during the shortest days, giving homeowners a natural window to give their mower some attention before packing it away. Skipping this step often leads to seized engines, rusted decks, and disappointing starts when the spring growth kicks back in.

A bit of preparation now saves money and frustration later. Petrol left sitting through the off-season gums up carburettors, damp invites corrosion, and a dull blade makes the first mow of the new season harder than it needs to be. The good news is that most of the work takes an afternoon and a few basic supplies, much of which you'll find at any Bunnings or Mitre 10.

Cleaning after the last cut

Before doing anything else, get the cutter deck clean. Caked-on grass holds moisture against the metal and, in Australian conditions where Kikuyu and Couch runners weave themselves stubbornly under the deck, this buildup happens quickly. Tip the mower on its side with the carburettor and air filter facing up. Check your owner's manual first, because the safe tipping angle varies between a Victa cordless model and a traditional four-stroke.

Use a putty knife or a stiff brush to scrape out the clippings, then hose down the underside and let it dry completely. Wipe down the engine housing, handles, and wheels. If you've been mowing through damp Buffalo grass, the residue can be particularly stubborn and may need a degreaser.

While the mower is clean, inspect the deck for cracks or rust spots. Small surface rust can be sanded and touched up with enamel paint, which also helps prevent the corrosion that salt air brings in coastal suburbs from Sydney to Perth.

Sorting out the fuel system

Fuel is where most stored mowers come to grief. Australia sells E10 petrol as the standard grade at most service stations, and that ten percent ethanol content is hygroscopic, meaning it attracts and absorbs moisture from the atmosphere. Left sitting for three or four months, E10 can phase-separate, leaving a watery layer at the bottom of the tank and a varnish-like residue in the carburettor.

You have three reasonable options. The simplest is to run the mower until it stalls from an empty tank, then restart it briefly to burn off whatever remains in the lines and carburettor. The second is to drain the tank completely and dispose of the old fuel at a proper collection point, since many council waste transfer stations accept it. The third, and arguably the easiest if you've filled up recently, is to add a fuel stabiliser such as Sta-Bil or a similar product available at Bunnings, run the engine for a minute to circulate it, and then store the mower with a full tank.

If you choose to drain, also remove the spark plug and pour a teaspoon of fresh oil into the cylinder, then pull the starter cord once or twice to coat the walls. This thin film prevents rust on the internal surfaces during the long months ahead.

Blade, oil, and air filter

With the fuel addressed, move on to the blade. Disconnect the spark plug lead first; this step is non-negotiable for safety. Then either remove the blade with a spanner or, on many modern mowers, use the dedicated blade removal tool that came with the machine. Sharpen the cutting edge with a file or bench grinder, keeping the original angle, and balance the blade on a nail or a purpose-made balancer before refitting. An unbalanced blade causes vibration that can damage the crankshaft bearings over time.

While the blade is off, take the opportunity to change the engine oil. Run the mower briefly to warm the oil, then drain it while warm through the designated plug or by tipping the mower according to the manual. Refill with the grade specified by the manufacturer, commonly SAE 30 for small four-strokes in Australian conditions. The air filter, usually a foam or paper element behind a side cover, should be cleaned or replaced. A clogged filter is one of the most common reasons stored mowers run poorly when restarted.

Choosing where to store it

Where the mower lives for the next few months matters as much as how it's prepared. The ideal spot is dry, sheltered, and out of direct sunlight, because UV degrades plastic housings and rubber components over time. A garage corner, a garden shed with a sound roof, or a covered verandah all work well.

Floor moisture is a common issue. Storing the mower on a piece of plywood, a rubber mat, or even a sheet of cardboard keeps the wheels and deck off cold concrete that can wick moisture and promote rust. In sheds that have copped the odd downpour, and many Australian sheds have, particularly after a wet La Niña summer, you might also want to think about whether water damage repair services are worth investigating for the structure itself, since a leaking roof can undo all your careful mower preparation in a single storm.

If rodents are active in your area, raise the mower off the floor and consider placing mothballs or rodent deterrent sachets nearby. Mice love to nest in air filters and chew through wiring, and a small investment in deterrent now beats rewiring a mower in spring.

Spring checks before the first mow

When the days lengthen and the lawn starts greening up again, resist the temptation to simply yank the starter cord. A short pre-season check catches anything that went wrong in storage and gets you back to mowing safely.

Refill with fresh petrol, and never reuse fuel that's been sitting for more than a few months, even if you added stabiliser. Check the oil level and the air filter. Inspect the blade for any new nicks or rust spots and confirm it's still sharp. Examine the wheels, the drive cable if you have a self-propelled model, and the safety interlock switches that prevent the blade spinning unless the bail lever is held.

This is also a good moment to walk around the yard and assess what needs attention. You might be wondering whether to replace that struggling tree, or whether the lawn itself needs renovation after a harsh summer. Both questions deserve their own careful thinking before you start the engine.

What to remember

The short version is this: clean the mower thoroughly, deal with the fuel properly so E10 doesn't destroy the carburettor, sharpen and balance the blade while you're at it, change the oil, and store it somewhere dry and shaded. Do a quick walk-around before the first spring mow and the mower should start on the first or second pull. A mower that's been put away thoughtfully will cut cleanly and last for many more seasons, which is far cheaper than replacing it after a winter of neglect.