Skip to Content

How to Change Oil in a Lawnmower

One fine day you plan to give your grass a nice trim. It’s been a while since you purchased your Lawn Mower, and you realize it is the right time to perform some routine maintenance. The first thing that comes to mind after hearing the word maintenance is an oil change. You haven’t changed your oil before and aren’t sure if you should do it yourself or take your mower to a mechanic who might charge extra bucks. If you’re a DIY kind of guy who is looking online for how to change the oil in a lawnmower, you’ve come to the right place.

Lubricant oil is often used for reducing wear and tear between engine parts. This process enhances the engine service life. During constant operation, the oil quality reduces. Therefore, changing your oil must be changed after 50 hours of operation (or once every season). You might need to change the oil after 25 hours of operation (twice every season) in case of frequent use. To change the lawnmower oil, you should follow these steps:

How to Change Oil in a Lawnmower:

  1. Warm up your engine and get the things you need for the job
  2. Drain the used oil by choosing the appropriate drainage method and following the safety precautions
  3. Fill the oil tank with the right kind of lubricant for your lawnmower to the desired level
  4. Allow the oil to settle and clean your worksite

Suppose you’re looking for an in-depth guide to the above steps. In that case, you should stay tuned to this article as we provide you with the information you are searching for in a user-friendly and straightforward language.

Steps to Change Lawnmower Oil:

You should follow the steps below that provide you with a detailed procedure and the precautionary measures to be taken care of while making an oil change.

1) Preparation for an oil change:

Before carrying out the oil change, you should ensure that you take the necessary precautionary measures:

● Step 1: Run your engine for a while:

Start your engine and keep running for a while (preferably for 15 minutes). This engine warming up will, in turn, warm up the oil. The oil moves more freely, and the draining process becomes easier.

● Step 2: Clean the oil fill area:

The oil cap often gets a lot of debris from the outside. Also, the area around it, being oily, often attracts dirt from the atmosphere. It would be best if you gently used a towel to clean that area and the fuel cap to remove the debris.

● Step 3: Keep your kit ready:

Depending on the process of your oil drainage, you should keep your equipment ready. If you want to remove the oil using the Siphon method, you should keep the siphon pump ready. In most cases, the oil is drained using the tilt method, so you should keep a pan for pouring the drained oil. You should also purchase the requisite oil grade for your machine by thoroughly undergoing your user’s manual. Most lawnmowers use SAE 30 detergent oils. However, you should only use the one recommended by your manufacturer.

You can watch this video to get a better understanding of the above steps:

2) Drainage of the used oil:

The oil drainage can be carried out either by using the siphon or tilt method. However, before you drain the oil, you should first follow the safety precautions as given below:

● Step 1: Remove your spark plug:

The spark plug needs to be disengaged during this process. This step ensures that your safety isn’t compromised since the spark plug connected might result in the engine accidentally starting up (most probably when the blades are rotated). Hence, disconnecting the spark plug provides you with an additional safety layer.

● Step 2: Secure the fuel cap:

You must thoroughly drain your gasoline before the oil change, especially during the tilt method. If that is not possible, it is also good to use a sandwich bag underneath your cap and then tighten it so there isn’t any chance of the oil leaking from the cap.

● Step 3: Perform oil drainage:

– Tilt method:

In this method, you tilt your lawnmower towards the side so that your air filter points upward (this prevents the fuel from entering the air filter). Afterward, you open the oil cap and allow all the oil to be drained into the pan. Make sure you do not make contact with the hot oil that can be damaging to your skin.

– Using the oil drain plug:

Not all lawnmowers are equipped with an oil drain plug. You should consult your user’s manual to identify the oil drain plug’s location in your machine. Generally, it is located below the deck of the lawnmowers. Again, it would help if you tilted the mower to its side to see the plug and remove any debris present around it. Then, use a hand tool to open the cap (with your mower placed upright) and allow the oil to be drained into a pan.

– Siphon method:

During this method, a siphon pump is put into use. These pumps drain the oil into an in-built tank from where it can later be drained off. You should manually suck the oil out by pushing/pulling the piston. It is a much cleaner and more efficient way of oil drainage, resulting in no oil spills in the work area.

Here’s a quick guide in this video:

3) Addition of fresh oil:

After purchasing the right oil for your lawnmower, the next step is adding fresh oil to the oil tank. Place your mower into an upright position and keep adding oil in small quantities. It would be best to keep checking your dipstick every time to visualize the oil level. Keep adding the oil until the desired level is achieved.

4) Cleaning up the work area:

After you’ve added the fresh oil, it is recommended to keep your mower upright for 5 minutes and let the oil settle. Recheck the oil level and replace your oil dipstick. Afterward, reconnect your spark plug and remove the sandwich bag around the fuel cap. Clean the oil spilled on your floor. It is advisable to take your drained oil to a recycling dealer.

You can refer to this video below to watch a practical demonstration of the whole process:

Related Questions:

1) What happens if you do not change the oil in a lawnmower?

If an oil change is not done for some time, the engine’s wear rate increases. Also, most lawnmowers do not have an oil filter. As a result, the quality of the oil deteriorates very quickly. Moreover, the oil is responsible for cooling the engine apart from the air-cooling. The engine’s life fall’s short of its manufacturer’s predicted lifespan. Hence, neglecting the oil changes in lawnmowers is not recommended.

2) Can you use car oil in a lawnmower?

SAE 30 motor oil is commonly used in a lawnmower. Some machines may use 10W-30 or 10W-40 oils as their user manual recommends. These oil types are often used in vehicles. Hence, they can be used in lawnmowers.

3) What is an SAE 30 oil?

SAE 30 is a motor oil with a viscosity value of 30, as rated by the Society of Automotive Engineers (SAE). These ratings are generally from 0 to 50. The viscosity refers to the thickness of the oil or its ability to flow. Thinner oils (with low viscosity) give better performance in cold weather.

In contrast, thick oils are used when the temperatures are high. SAE 30 is a single-grade oil that is thicker than lower grades. It is typically used in small air-cooled engines such as lawnmowers and chainsaws. Most motor oils are multi-grade, i.e., they can perform in all seasons.

4) Is SAE 30 the same as 10W-30?

10W-30 indicates that the oil has a viscosity of 10W when the engine is cold and 30 when it is hot. It would help if you considered factors such as temperature while making this choice. SAE-30 is a single-grade oil suitable in conditions where its high temperature and the variation aren’t significant.

Whereas, if your weather keeps varying, you may use 10W-30. It also improves cold-starting at lower temperatures as compared to SAE-30. Hence, if you’re living in moderate or milder climates, using SAE 30 or 10W-30 won’t make much difference regarding engine performance.

5) Is a lawnmower engine 2-stroke or 4-stroke?

Lawnmower engines come with both designs, i.e., 2-stroke and 4-stroke. In a 2-stroke design, the entire cycle of combustion and power is completed in the crankshaft revolution. A 4-stroke takes two revolutions of the crankshaft for the whole cycle to complete.

In the case of 2-stroke engines, oil is mixed with gas as there is no separate reservoir. In comparison, 4-stroke engines require an oil reservoir to thoroughly lubricate the connecting rods and crankshafts.

Final Remarks:

Oil changes are significant at the right time as they ensure that your engine components undergo minimum wear and tear. Also, the overuse of low-quality oil for a long time can result in engine servicing that might be costly. Hence, you should always keep a check on the working pattern of your lawnmower. It is better to replace oil at the beginning of every season.

In the case of overuse, you might need an oil change in the middle of the season. Ensure that you use the right oil type and always follow the safety precautions while replacing the oil. “Prevention is always better than the cure” is the principle you should use, whether it’s maintaining yourself, your car, or your lawnmower.