Lawn mower maintenance is a must to keep yours in top working order. Following a regular maintenance schedule will help to prolong the lifespan of your lawn mower, and prevent accidents from occurring due to worn or damaged parts.

In this guide we’ll cover the most important petrol lawn mower maintenance tasks, ranging from day-to-day care to full lawnmower servicing. We’ll give you lawn mower maintenance tips, and tell you how to sharpen lawn mower blades. You’ll also learn how to inspect, service and replace engine components yourself.

Understanding Petrol Lawn Mower Maintenance

A petrol lawn mower requires regular maintenance to ensure that all components are working properly for optimal performance. Its internal combustion engine needs the same sort of care as your car’s engine, and the blades need to be maintained for maximum cutting efficiency. This not only benefits your lawn mower – cleaner, more precise cutting also helps to keep your grass in a healthy condition.

Other benefits of proper lawn mower maintenance include lower costs overall. If you maintain your lawn mower, you’re likely to save a fair amount on repairs or parts replacement. Prolonging the lifespan of your lawn mower will also obviously save you from having to buy a new one prematurely.

Do Lawn Mowers Need Servicing?

Like any machine, a lawn mower should be serviced regularly. Lawnmower servicing is essential to detect worn or damaged parts, and replace them so that your lawn mower continues to work smoothly.

Regular lawnmower servicing can also reduce the cost of later repairs. If you keep yours in good nick, you’re far less likely to have to replace major parts. A well-maintained machine also makes it easier to detect and fix potential problems, saving on labour time and costs. You’ll also extend your mower’s lifespan.

How Often Should I Do Lawnmower Servicing?

Lawn mower manufacturers, like Sanli and Greenworks, provide maintenance schedules in your owner’s manual.

Most suppliers recommend that you service your lawn mower every 12 months. If you use your lawn mower a lot, it may be better to do a lawn mower maintenance service more often.

What Maintenance Does a Lawn Mower Need?

General lawn mower maintenance isn’t complicated. It only requires a few simple procedures.

First, you’ll need some basic tools:

  • Rags and a soft brush
  • A wire brush
  • Safety gloves
  • WD40 lubricant

Before you begin, make sure that your lawn mower is safe to work on, by checking that the throttle is in the “Off” position For extra safety, disconnect the spark plug too.

Step 1: Clean the outside of your lawn mower

Use your rags and a brush to clean the lawn mower’s outer casing and wheels, removing any grime or vegetation.

Step 2: Lubrication

To lubricate external working parts, all you need to do is spray WD40 onto the throttle cable, the wheels and the height adjuster. Make sure not to leave any excess – wipe it away with a rag.

Step 3: Inspect the spark plug

Remove the spark plug and make sure that it’s clean. You can use the wire brush for this. Replace it if you need to.

Step 4: Clean the air filter

Remove the air filter cover and check it for dirt. If necessary, remove the air filter, give it a few taps and clean it with a soft brush. If it’s really clogged, though, rather replace it.

Step 5: Clean the grass catcher

Remove the grass catcher container from the back of your lawn mower and give it a thorough brushing. If it’s very dirty you can hose it down too.

Step 6: Clean the underside

Put your lawn mower on its side to check and clean underneath the blade protector. Use a brush to remove grass or other vegetation, and make sure to clean the blades too. Wear safety gloves when working on this part of your lawn mower.

How Do I Service a Petrol Lawn Mower?

Thankfully petrol lawn mower servicing is not difficult or expensive. First read your owner’s manual, as it will contain servicing instructions specific to your make and model.

Servicing is usually a standard process…

1. Disconnect the spark plug

This is both for maintenance and personal safety. Before servicing, disconnect the spark plug to avoid the risk of the engine starting up unexpectedly. Use this opportunity to clean your spark plug or replace it if necessary.

2. Remove any external debris

Before inspecting other components, remove any vegetation or other debris with a brush. You should in any case do this every time after you’ve used your lawn mower.

3. Check and tighten loose components

Make sure that all the nuts and bolts are tightened, to prevent them from coming loose while you’re using your mower. Pay special attention to the wheels. Make sure that they’re well affixed and can rotate freely and evenly.

4. Check and clean the air filter

The air filter plays a crucial role in lawn mower maintenance by preventing dust and debris from entering the engine system. Remove your air filter from its housing and dust it off with a brush. Clean the housing as well.

5. Check the starter cord

Inspect your starter cord for any signs of fraying. To replace it, simply remove the pulley system housing, take off the old cord and insert the end of the new one into the pulley. Then wind it around the pulley a few times.

6. Replace the oil

Look at your owner’s manual to locate the plugs to the oil reservoir. Place a bucket underneath them before opening and letting the oil drain out. Pour in new oil to the correct level using a funnel.

How Often Should You Change the Oil in a Petrol Lawn Mower?

It’s recommended that you change the oil in your petrol lawn mower at least once a year, typically at the start of spring. As a further rule of thumb, you should change oil after every 50 hours of use.

Place the lawn mower on a flat surface to let the oil settle. Read the manual for the location of the dipstick and check the oil level. If you need to add oil, check which type the manufacturer recommends in the manual. Remove the oil cap and slowly top up using a funnel.

Do I Need to Drain Petrol from a Lawnmower?

It’s always a good idea to drain the petrol from your lawn mower between uses, especially if you don’t use it often. Petrol left in the tank can degrade within 30 days. Running your lawn mower on degraded petrol can damage it, so rather drain the petrol after each use to be completely safe.

You can use a syphon pump to transfer the petrol from your lawn mower to an external cannister. Before you do this, turn the fuel shut-off valve to the “Off” position, if you have one, and make sure to remove the spark plug. Or empty the petrol by tilting the lawnmower and pouring it into a draining pan or a funnel.

Life Expectancy of a Petrol Lawn Mower

In general, petrol lawn mowers last for around 10 years, provided they’re properly maintained. However, this also depends on usage. You can expect a lifespan of roughly 450-500 hours of use. Regular maintenance can help to extend this further.

Replace or Repair – Which is Better?

It’s usually cheaper to repair lawn mower components yourself. However, if this is beyond your ability, you’ll need to pay repair costs. The choice of whether to replace or repair hinges largely on the condition of the components and the age of your mower. Consult professionals who can accurately advise you on whether you need to replace parts.

Correct Ways of Lawn Mower Blade Sharpening

Sharpening is an important aspect of lawn mower blade maintenance, and you don’t need many tools to sharpen lawn mower blades.

As always, make sure that the lawnmower power is off, and remove the spark plug. Then put a wooden block between the mowing deck and the blade to prevent any movement, and use a wrench to loosen the central nut and remove the blade.

Put on safety glasses and gloves and clean the blade before sharpening. A simple metal file is the best tool to use. Make sure to file in the direction of the cutting angle, and sharpen both sides. The blades don’t need to be razor sharp – only about as edged as a butter knife.

Can You Sharpen Mower Blades Yourself?

Yes, as detailed above, it’s pretty easy to sharpen your lawn mower blades yourself. You’ll only need the abovementioned tools. Regularly sharpening your blades is an important part of DIY lawn mower maintenance, and will also help to ensure clean-cut and healthy grass.

Can You Sharpen Mower Blades Without Removing Them?

It’s not recommended that you try to sharpen mower blades without removing them. If they’re still attached it can become an unwieldy task, as access is awkward and the blades can move around.

To Sum Up:

Proper lawn mower maintenance goes a long way to ensuring the machine’s longevity, reducing overall costs, helping to prevent injuries, and keeping your grass healthy. It’s a pretty easy DIY job – as long as you follow the right procedures, you’ll have many happy years of use from yours.