How do I put a lawnmower away for the winter?

Winterising a mower is really about one thing — getting the fuel out — plus a handful of jobs that are far pleasanter in October than on the first warm Saturday in April. The whole thing takes an hour and it is the difference between a machine that starts first pull and a service bill.

Safety

What you'll need

• A fuel container
• Fresh engine oil of the correct grade
• A container for the old oil
• Stiff brush, scraper and rags
• A new spark plug and air filter (optional)

Step by step

1. Run the fuel out rather than leaving it in.Outdoors, let the machine run until it stops of its own accord. That empties the carburettor bowl as well as the tank, which is the part that actually varnishes up. If you would rather drain it, drain the tank first and then run it until it stops.
2. Or dose the tank with stabiliser if you cannot drain it.Add stabiliser to a full tank, then run the engine for ten minutes so treated fuel fills the carburettor. A part-empty tank left over winter collects the most condensation of all.
3. Disconnect the plug lead and clean the deck.Scrape the compacted grass off the underside with a wooden or plastic scraper. Dried grass holds moisture against steel all winter and is a major cause of rusted-out decks.
4. Clear the cooling fins and the recoil housing.Brush the grass out from between the cylinder fins and from under the starter cover. It insulates the engine and causes overheating, and winter is when you have time to do it properly.
5. Change the oil while the engine is warm.Warm oil carries the suspended dirt out with it. Drain it into a container, dispose of it at a household waste site, and refill to the mark with the grade in the handbook. Old oil left in over winter is acidic and sits on the bearings for months.
6. Deal with the blade now.With the plug lead off, remove the blade — noting which way round it fits — and either sharpen it along the existing bevel or replace it. Check for cracks or deep nicks; a cracked blade is scrap, not a sharpening job. Balance it before refitting: a blade sharpened unevenly vibrates the engine to pieces.
7. Service the air filter and the plug.Wash and re-oil a foam filter or fit a new paper one. Fit a new spark plug — it is a small cost and it removes one variable from the spring start.
8. Lubricate the cables and pivots.A drop of light oil on the throttle and drive cables, the wheel height adjusters and the handle pivots. Everything on a mower seizes over a wet winter.
9. Wipe the exposed metal.A rag with a trace of oil over the deck and the blade prevents surface rust. Do not soak it — oil attracts dust.
10. Store it dry, off the floor.A dry shed or garage, on a board or a pallet rather than directly on concrete, which draws and holds moisture. Cover loosely with a breathable sheet, never wrapped tightly in plastic.
11. Take a cordless mower's battery out.Store the battery separately at around half charge, somewhere cool, dry and above freezing — and not in the house on an escape route. Check it once or twice over the winter and top it up if it has drifted very low.
12. Make a note of what you did.A label on the handle saying what you changed and when. It answers next year's questions in three seconds.

Tips

• Do it on the last cut of the year while the engine is warm and you are already outside. It takes half the time.
• Order the blade or the plug in autumn, when they are in stock, rather than in April when everyone wants one.
• If you take it for a service, book it in winter. Mower workshops are overwhelmed from March onwards.

Common mistakes

• Leaving a part-full tank of petrol in over winter — The air space above the fuel breathes moist air in and out with every temperature change, the ethanol absorbs it, and the fuel separates. The resulting varnish in the carburettor jets is the standard reason mowers do not start in spring.
• Storing the machine directly on a concrete floor — Concrete wicks moisture up continuously, and the underside of the deck stays damp all winter. A pallet, a board or a couple of battens solves it for nothing.

If it doesn't work

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