A Useful and Gradual Guide On How To Change Oil in Generator

Even though now more and more manufacturing companies are trying to increase the shelf life of the generator and reduce their wear, things like engine oil remain relevant for all users even with different models of devices.

Have you ever had a situation where the engine could stall in the middle of the work and at the same time the owner’s manual says there is not enough oil in the generator?  If the answer is yes, then this article will help you.

In this article, you will be able to understand how to change the oil correctly, as well as additional information on how to choose the right oil and fuel for your generator.

Why Do You Need Oil For The Generator?

The oil and an oil filter should be used for the generator, since, firstly, it improves its operation, and secondly, engines wear out much less from oil.

This is due to the reduction of friction, that is, any obstacles to the operation of the generator are destroyed. Without oil, small parts inside the engine begin to rub against each other and can simply come off, getting stuck in the generator system itself.

When buying a new portable generator, it is very important to check either the owner’s manual or yourself whether there is oil inside, so as not to break it the first time you use it, since the maximum normal engine operation time without oil is half an hour, which even then cannot be guaranteed to be harmless use.

How To Understand Which Type Of Oil My Generator Needs?

To begin with, you need to understand under what conditions and temperature you will use engine oil, since different oil viscosities can be convenient, for example, in winter, and in summer, on the contrary, lead to engine failure.

Of course, you can do your research and find out, for example, that it is better to use 5w30 in winter, but in any case, it is best to refer to the owner’s manual and see which oil is right for your engine, since even the right viscosity level does not always guarantee full power and performance of the generator.

Type Of Oil My Generator

Instructions On Changing The Oil In The Generator

Instructions On Changing The Oil In The Generator

Finally, we come to the main answer to the question of how to properly change the oil in the generator’s engine. It is very important to follow all the instructions and make sure that the engine oil is completely suitable for your generator.

This process can be used in different generator brands including, Generac, Honda, Onan, Champion, Predator, and Fireman. 


Below, you can find a list of tools that are very important to have before you start changing the oil.

  1. Protective gloves
  2. New engine oil
  3. Brush and towel
  4. Flat screwdriver
  5. Goggles
  6. Oil drain plug
  7. New oil filter
  8. Oil funnel
  9. Oil filter wrench
  10. Socket wrench
  11. Oil fill cap
  12. Spark plug

Time Duration:

You will only need 10 minutes for this process. 

Here’s a hack. If you need to run the generator urgently but have a low oil level, you can bypass the oil sensor for a while. But don’t do it for long. 

Step-By-Step Guide:

If you are sure that you have all the materials from the list, then you can begin to familiarize yourself with the detailed steps that will help you change the generator’s engine oil safely, and most importantly, it is harmless to the generator.

Start the Generator With Old Oil: 

Before you will start to change the generator oil directly, the first thing you need to do is start the generator with the old oil inside so that it starts to heat up within a few minutes, but keep a close eye on the engine so that the heating of the old oil does not damage it.

This must be done so that the old oil drains more easily and, as a result, it is easier to remove it, since it will be in a more liquid state of aggregation.  If the oil is cold, there is a chance that the frozen pieces may be unnoticed by you and eventually lead to engine failure. 

When you realize that the oil has warmed up enough, you need to immediately turn off the generator.

Prepare The Space Around The Generator: 

Now, to perform an oil change, you need to put your generator on a special design, like blocks, but at the same time save free space and make the path for draining oil from the plug unobstructed. 

The structure must be installed on a level and stable surface so that you can be sure that the generator is firmly located.

Generators are almost always very heavy, so you need to understand in advance exactly how it is best to transfer the generator. You can use the help of special mechanical structures or simply ask other people for help. 

You risk not only harming the generator itself if it is unsuccessfully transferred to another place but also harming itself.

Put The Spark Plug On Idle Mode:

You need to make sure that the generator will not be able to start in any way and for this, you need to put the spark plug in idle mode.

Most often, the location of the spark plug can be found on your own, sometimes they are hidden under special “covers” in the form of a cap, however, if you cannot find the spark plug, then just look for your generator model and then find the instructions specifically for your generator to turn off the ignition.

Now you need to take the wire that is connected to the spark plug and disconnect it from it. To do this, turn it in different directions and then pull it towards you. Do this carefully and without too much harshness, if you just start pulling the wire towards you with force, you will break it. Make sure the wire is away from the spark plug.

Drain Old Oil:

You need to find and clean the drain plug. If you’re having trouble locating the drain plug, just like with your spark plug, just look up information about your specific generator model. Also, after cleaning, put the oil pan under the cork so that the old oil does not stain you and the area where you are.

You can also use the drain pan or any other container, that will be useful and deep enough to collect all the oil.

After that, you can start draining the old oil. Cleaning the plug was necessary to reduce the obstacles for the oil to escape, however, if you want to speed up the process of eating more, you can remove the oil filler cap, but do this carefully.

Remove the Oil Plug:

The final step to start the process of pouring out the old oil is to remove the oil plug. Take the socket, and ratchet, and make sure these tools are right for your type of drain plug. 

Loosen the oil plug with a ratchet, and now you can get rid of the threads yourself, be sure to remove the ratchet and socket first.

Have a drain pan ready as the oil may start to spill out of nowhere. Make sure that you have collected all the oil and no more spills from the generator, as this liquid pollutes things and the environment very much. 

That is why after the container is filled with oil it is better to immediately find a place for its processing.

Change The Old Oil Filter:

If you have an old oil filter, then you better change it. To do this, make sure you have a drain pan, as oil may pour out while removing the old filter from the generator. 

Take pliers or a wrench and loosen the filter fasteners, then unscrew it completely yourself. After that, install a new filter, but be sure to tighten all parts tightly enough with a wrench.

Changing the filter is very important, even though many drivers consider it a waste of money, if you use new oil but pass it through the old filter, it will deteriorate faster, causing the generator itself to wear out faster.

Pour The New Engine Oil In Generator:

Engine Oil for Generator

Finally, we have come to the main stage, namely the use of new oil for your generator. First of all, you need to install the oil drain plug back in case you removed it when installing a new filter.

This is necessary so that the oil does not spill out of the filter once again. After that, you need to open the oil fill cap and install a funnel inside so that the oil gently fills the generator and does not spill out in different directions.

As we said earlier, the new oil must be ideal for your particular model of generator, since you already have been able to understand that changing the oil is a long and energy-consuming process, so it is better to use a quality product right away.

Connect Spark Plug Wire:

Spark Plug Wire

The last step is to connect the spark plug wire free again. To do this, take one end of the wire plug and insert it into the desired holes, you will hear a click, which will indicate that the spark plug wire is perfectly connected. 

Now you need to replace all the protective mechanisms of the spark plug, such as covers.

Run your generator’s engine for a few seconds, allowing the oil to properly distribute throughout the generator. It is also important to check if you have filled in enough oil fluid, for this you need to know the correct range of your particular engine. 

If there is too little oil, repeat the previous step, but if there is too much oil, repeat all the previous steps related to draining the old oil.

Here’s the whole process of changing the oil in the generator. Here’s a tip. It is good to know beforehand, how much gas the generator use. For example, how long the runtime will be for 5-gallon gas? It helps you be cost-efficient. 


We hope that after reading this article, now you know how to change the oil in the generator. Also, be very careful about the type of oil you use. Also, maintain the interval for an oil change. 

That’s all for now. Have a great day!

Frequently Asked Questions (FAQs):

How Often Should I Change The Oil In My Generator?

It all depends on what model your generator is and what year, however, it is best to change the generator oil every week, frequency of changing the oil filter depends on the manufacturer.

What Happens If You Don’t Change Oil In the Generator?

If you forgot to change the oil and oil filter once, there may be no consequences, but with the constant practice of avoiding oil changes, your generator will wear out quickly.

Should You Run The Generator Before Changing The Oil?

Yes, to warm up the old oil and make it glass faster; however, this process takes a couple of minutes, and it is better to be careful not to heat the generator oil filter too much. This action is not mandatory, but it will just help you get rid of the old oil more easily.

What Is The Second Step In Changing The Oil Of A Generator?

The second step in changing the oil and oil filter is disconnecting the spark wire plug from the generator, which stands on a special block and has a drain pain for old oil.

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