How To Service Your Lawn Mower

In our latest video, we demonstrate how to service your lawn mower. 

We remove the spark plug, replace the air filter, replace the blades, change the oil and finally replace the spark plug. 

For this process we used a Hyundai HYM51SPE Electric Start Petrol Mower, but the techniques should apply to almost all domestic petrol lawn mowers. 

Removing The Spark Plug 

The first thing to do is remove the spark plug. 

Locate the plug, which is found at the front of the machine on the front of the engine. 

Remove the HT Cap by firmly pulling it off and then remove the spark plug by by placing the long-reach spark plug wrench over the plug and turning it anti-clockwise to loosen it. 

Be careful to keep this wrench straight to avoid putting strain on the ceramic insulator, as this is quite fragile. 

Replacing The Air Filter 

Next, we’re going to replace your air filter. 

The air filter is usually towards the front of the engine on one side. To make it easier to find, it’s usually opposite the side where your exhaust is located.

To remove the air filter covering, simple unclip the outer cover. This will reveal the air filter, and to replace just reverse the above, being careful not to allow and dirt into the air intake.

Replacing The Blade 

Now it's time to replace the blade.

To do this, you're going to have to tip the lawnmower on its side. 

Warning: You don’t want to replace the spark plug before this step as, if you accidentally turn the crank, there is a chance you could start the engine up and have the blade spinning, which is obviously very dangerous. 

Always keep your spark plug out when dealing with your blade so there’s no chance of this happening. 

To remove the blade, make sure you always wear heavy-duty gloves, undo the centre bolt by turning it anti-clockwise and safely pull the blade plate off. 

Once you’ve done this, take your new blade plate and thread the bolt back on, making sure the new blade plate is safely attached. 

Ensure this is tightened to the correct torque as stated in the manual. For this machine it is 40ft-lb. 

Changing The Oil 

To change your oil, first locate your dipstick which can be on the top, side or back of your lawnmower. 

You’ll need a syphoning syringe to suck the oil out. 

Remove the dipstick, stick the syringe down until it goes no further and simply by pulling it up you’ll be draining the lawnmower of oil. 

Once you have removed all of the oil, you’ll have to replace it with new oil. Always make sure the new oil you put in goes up to the correct marker on the dipstick. 

Once you’ve done that, screw the dipstick back in to place. 

Replacing The Spark Plug 

Finally, we return to the spark plug. 

Put your new spark plug in the spark plug hole and begin to tighten it in by hand until you can feel it’s quite tight. 

The reason for this is to ensure you’re screwing the spark plug in correctly so that it won’t cross thread. 

Once it’s tight, tighten it with your deep socket and replace the HT cap. 

Once you’ve done all of these steps, you are ready to take your lawn mower out in to your garden for the rest of the season.