How often should you service your lawnmower?

Why bother

Old oil and a fouled plug make it a pig to start. A thorough-tier job. Skippable when life's busy, worth it when it isn't.

Why it's a range

Big lots or dusty work want a mid-season touch. The plug can go two years.

What the job involves

1. Drain the old oil and refill, swapping the oil filter if the mower has one, then check the level on the dipstick. This is the cheap job that saves the dear one.
2. Clean or replace the air filter so the engine can breathe, and pull the spark plug. If it's fouled, fit a new one and set the gap to the manual's number.
3. Sharpen or replace the cutting blade, then scrape the caked grass off the underside of the deck. A clean deck and a keen blade cut, a dull one tears.
4. Sort the fuel: stabilizer if it's sitting more than a month, or run the tank dry for off-season storage. On a riding mower, check the belts and the tire pressure while you're down there.

Do it yourself, or pay someone?

DIY for most people: oil, air filter, spark plug and a blade sharpen are hand-tool jobs, roughly $30 to $50 in parts. Pay a pro if it's a riding mower, you've no comfortable spot to work, or you'd rather not handle the blade. A tune-up averages about $130, basic service $50 to $200, a full one $150 to $300, plus $30 to $100 if they collect it.

What skipping it costs

$300 to $1,000 and up is what the neglect costs once it lands. Run the engine on old, gritty oil and a clogged air filter and the grit works like sandpaper inside it: more friction, more heat, faster wear, until a fixable seized engine or major part at the low end, or a full engine replacement at the high end. Past that, a cracked crankshaft or a blown head gasket runs higher still, and most people just buy a new mower at that point. An annual service runs about $50 to $300, or $30 to $50 if you do it yourself. The oil change is the cheapest job on the list and the one that keeps the dear repairs away.

Signs it's overdue

• Hard to start, runs rough, stalls, or feels down on power compared to last season.
• Grass tips look ragged and turn brown a day or two after a mow. That's a dull blade tearing the grass instead of cutting it.
• Black smoke, oil gone dark and gritty on the dipstick, or the engine running hot. That points to a clogged air filter or choked cooling fins.

When to start thinking about it

Give yourself about 7 days' notice. That's when Grumpty starts grumbling, so it doesn't land on you the day it's due. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.

Questions people ask