Your lawn mower works hard from March through October here on Vancouver Island. In Nanaimo and Lantzville, the mowing season typically runs eight months — longer than most of Canada. That's a lot of hours on the engine, a lot of passes on the deck, and a lot of debris building up on the underside. Yet most homeowners do nothing between seasons except run the mower until something stops working.
A well-maintained mower cuts cleanly, uses less fuel, and lasts years longer. A neglected one tears grass rather than slicing it — leaving ragged, frayed tips that turn brown within a day or two and open the door to disease. In our coastal climate where cool-season grasses are already under stress from dry summers and restricted watering, that difference is real.
Here's the full seasonal maintenance routine, step by step.
Step 1: Disconnect the Spark Plug Wire First — Every Time
Before you touch the blade, tip the mower, or reach under the deck for any reason, pull the spark plug wire off the plug and move it away. A mower blade can spin unexpectedly if the engine turns over — even slightly. This five-second safety step is non-negotiable. Do it every single time you work on the machine, not just during formal maintenance sessions.
Step 2: Clean the Undercarriage and Deck Housing
Tip the mower on its side with the carburetor side facing up (this keeps oil from pooling in the wrong places — check your manual if you're unsure which side that is). Use a putty knife or stiff wire brush to scrape away the thick mat of compacted grass and soil from the underside of the deck.
This caked-on debris restricts airflow around the blade, causes clumping in wet conditions, holds moisture against the steel deck, and accelerates rust. It also reduces cutting efficiency — a clean deck creates better suction, which lifts the grass upright for a cleaner cut.
Do a thorough undercarriage clean at the start and end of each season, and a quick scrape after every few mows during the heavy part of the season. It takes three minutes and makes a noticeable difference.
Step 3: Inspect and Sharpen the Blade
This is the single most impactful maintenance task on the list. A sharp blade cuts grass cleanly. A dull blade bludgeons it, leaving torn and frayed tips that dry out and give the lawn that whitish, scorched look — especially visible a day after mowing.
Remove the blade bolt and take the blade out for inspection. Look for:
- Nicks or dents from hitting rocks or roots — file these smooth
- Cracks in the blade metal — replace immediately; never run a cracked blade
- Visible bends — replace the blade; a bent blade vibrates severely and will damage the crankshaft bearings over time
- Dull edges — the cutting edge should feel similar to a butter knife, not sharp like a kitchen knife, but clearly defined and smooth
Sharpen dull edges with a metal file or bench grinder, maintaining the original bevel angle (typically 30–45 degrees). Work in smooth strokes from the top of the cutting edge downward.
After sharpening, check blade balance: hang the blade on a nail driven into a wall, through the centre hole. A balanced blade hangs level. If one side drops, remove a small amount of metal from that side until it balances. An unbalanced blade vibrates at high speed, and that vibration is what destroys bearings and shortens engine life.
Aim to sharpen at the start of each season and again mid-season — around June or July in Nanaimo. If you hit a rock or a hard stump root, sharpen again immediately.
Step 4: Change the Engine Oil
Lawn mower engines need fresh oil once per season, or every 50 hours of use — whichever comes first. With an eight-month mowing season in our area, once per season is the minimum. If you're mowing weekly, you may accumulate more than 50 hours in a single season.
Run the engine for two minutes to warm the oil so it drains fully, then tip the mower to drain through the fill hole or use the drain plug if your model has one. Most small engines take SAE 30 or 10W-30 oil — check the manual for the correct grade and how much the engine holds.
Fill to the dipstick mark. Don't overfill — excess oil can foul the spark plug and cause the engine to smoke. Fresh oil is pale amber. If what came out was black, sludgy, or smelled burnt, you were overdue.
Step 5: Service the Air Filter
A clogged air filter starves the engine of air, causing it to run rich, burn more fuel, lose power, and produce excess smoke. Checking the filter takes two minutes.
Most mowers have either a paper filter element or a foam pre-filter, or both. Paper filters: tap them gently against a flat surface to knock loose dust and debris, and hold them up to a light source. If light doesn't pass through clearly, replace it. Foam pre-filters can be washed in warm soapy water, squeezed dry (don't wring), and lightly re-oiled with a couple of drops of clean motor oil before reinstalling.
A fresh air filter is one of the cheapest ways to keep an engine running at full performance through a long mowing season.
Step 6: Check and Replace the Spark Plug
Remove the spark plug using a spark plug socket. Inspect it for:
- Heavy carbon buildup (black, sooty coating on the electrode) — indicates a rich-running engine or an old plug
- A cracked ceramic insulator — replace immediately
- Electrode gap — check against the spec in your manual, typically around 0.030 inches (0.76 mm); adjust if needed
Spark plugs are inexpensive — usually just a few dollars. If yours is more than two or three seasons old, replace it regardless of condition. A fresh plug means cleaner ignition and easier cold starts on cool spring mornings, which is exactly when you need it in Nanaimo.
Step 7: Test the Cut Before You Start the Season
Reconnect the spark plug wire, top up with fresh fuel, and do a test pass over a small section of lawn. Listen for vibration or unusual engine noise. Check the cut quality by looking at the grass tips — clean slices or torn fraying? Inspect the undercarriage after the pass to confirm it stayed clear.
Running this check in mid-March puts you ahead of the first real mow of the season, which typically falls in late March or early April across Nanaimo and Qualicum Beach. There's nothing more frustrating than pulling the mower out when the grass is ready and finding it won't start properly.
One Thing Most Homeowners Overlook: Fuel Storage
If you're storing the mower for the winter break — usually December and January in our mild coastal climate — run the fuel tank completely dry or add a fuel stabilizer to the existing fuel and run the engine for a few minutes to circulate it through the carburettor.
Stale gasoline left in the carburettor over winter turns into a varnish-like residue that gums up the jets and passages. The result: a mower that cranks but won't start in spring, requiring a carburettor clean or replacement. This is the single most common cause of spring starting problems, and it's entirely preventable.
Every few mows: Clean undercarriage. Once per season: Change oil, service air filter, check spark plug. Start and mid-season: Sharpen blade. Before storage: Run fuel dry or stabilize. After any rock hit: Inspect and re-sharpen blade immediately.
When It Makes Sense to Hand It Off
A well-maintained mower makes the whole mowing season easier — but the appeal of not having to think about any of this is real. Grasscycling and mowing height matter too, and a professional crew handles all of it automatically. West Coast Landscaping takes care of regular lawn mowing for Nanaimo, Lantzville, and the surrounding area — sharp blades, consistent timing, full cleanup after every visit. If you'd rather spend your weekends somewhere other than the garage, we can set up a schedule that keeps your lawn looking sharp all season.