How do you change the oil in a Predator 3500?

Generally, preventative maintenance includes a regular inspection of your inverter generator. You ought to check the oil levels, coolant level, fuel system, and starting system to ensure that it maintains peak performance.

One of the maintenance practices that ensure consistent peak performance of your Predator 3500 is the replacement of old oil. Other than making your generator reliable and efficient at all times, fresh oil lubricates the vital parts of the engine and ensures that the starting process is as seamless as possible. The owner’s manual includes information on the desired all type, how much oil you should put in the generator tank, the oil filter type, and the rate at which you should replace the oil. In this article, we will explain an easy-to-follow process that you can use to change the oil in your Predator 3500 inverter generator. So, how do you change the oil in a Predator 3500?

To change the oil on your predator 3500, you need to replace the oil filter, drain the old oil, and put fresh oil into your generator.

Before all else, which oil does the Predator 3500 generator use?

The Predator 3500 inverter generator runs seamlessly on the SAE 10W-30 engine oil type as well as the synthetic high mileage 10W30 engine oil or the 0W40. Generally, the type of oil that your inverter generator needs tend to change depending on the weather and seasons. When the temperatures are too cold, you are advised to use a lower viscosity oil to maintain the performance and efficiency of your generator. When the temperatures are hot, on the other hand, your generator may require higher-viscosity oil.

When should you change the oil in your Predator 3500 generator?

Manufacturer specifications found in the owner’s manual are the only guide that you should use to determine when and how to change your generator oil. You need to constantly check whether the oil is running out or keep tabs on the indicators before adding the required amount of oil as per the manufacturer’s instructions.

That said, you should at least try and change the oil on your generator at least once every spring or summer (when the temperatures are hot), depending on which of the two comes first. Most new inverter generators need their first oil change after the first 25 hours of operation. Beyond that, you will have to get rid of the old oil remains and refill the tank after every 50 to 60 hours. Once you have changed the oil, ensure to maintain the routine if you want to keep your engine healthy. Also, ensure to store up enough oil and factory filters to last for a couple of days.

In addition to that, most generator experts recommend that you do a full oil change after every 100 hours of use, especially if you run your generator every day or tend to use it for overnight and heavy-duty applications. For safety purposes, ensure that your generator has cooled off completely before doing an oil change.

So, how do you change the oil in your Predator 3500 generator?

Once you have your protective gear on, the following steps should get you through the oil change process;

Step One: Heat the old oil in the generator tank

Generally, hot oil has a lighter and more viscous consistency which makes it easier and faster to drain. Also, the oil should be hot enough to shut off the generator. To do this, start up your Predator 3500 and let it run for approximately 15-20 minutes so that the oil can warm up.

Step Two: Place your generator on an even surface then unplug the spark wire

You can use a few blocks on a sturdy table to ensure that there is enough space under the plug draining oil. Once your generator is stable, find the spark plug and unplug it. Doing this prevents any accidental generator starts, especially when there is low oil in the tank, which could tamper with the process. If you find any trouble locating the spark plug on your Predator 3500, you should consult with the owner’s manual. When unplugging the wire, do it carefully to avoid pulling out a portion of the wire and try to prevent direct contact with the spark wire and the plugs during the oil change process.

Step Three: Drain the oil from the tank

At this juncture, you need to find the 3/8 inch plug draining the oil. Check whether it is soiled or has some oil residue. If it does, clean it out before draining the oil. Also, ensure to place an empty oil pan or any leakproof container right below the drain plug. You can also take out the oil filler cap if you want the oil to drain much faster. Once you have collected all the old oil, take it to a place where it can be recycled.

Step Four: Replace the oil filter

Running new oil into your generator using an old oil filter may contaminate it. For this reason, it is important to replace both the oil filter and oil simultaneously. Not only does it prevent contamination, but also prolongs the lifespan of your generator engine. When doing this, ensure to have gloves on because the filter may be hot. Also, use your pliers to tighten the screw to prevent the oil filter from falling off. Once done, remember to dispose of the filter off at the nearest petrol station or a local recycling store next to you.

Step Five: Pour in new oil into your Predator 3500

After removing the oil fill cap, insert a funnel that you will use to pour oil into the generator. As mentioned earlier, you will find full information about the recommended oil for your generator from the owner’s manual. In this case, you will be using the engine oil type SAE 10W-30, or the synthetic high mileage oil 10W30 or the 0W40 type.

Step Six: Reconnect the spark plug wire before re-starting your generator

After reconnecting the spark plug, reattach all the covers that you had previously removed from your generator. Once all the parts are intact, start your generator and allow it to run for about 15-20 minutes. Doing this cleans the oil and lubricates the vital parts of the engine. After 20 minutes are over, turn off the generator and confirm using the dipstick whether the oil is within the recommended range. If not, keep adding the oil until it reaches the required level.


Regularly changing the oil in your generator maintains peak performances, ensures reliability, and prolongs the life span of your generator. The table below gives a summary of what we have discussed in this write-up.

Type of Oil
Amount needed
When to change
How to Change
Changing the oil for Predator 3500 generator
SAE 10W-30 engine oil, or synthetic high mileage oil 10W30 or the 0W40 engine oil
12 Quarts
After the first 25 hours of operation

After every 50 to 60 hours or after every 100 hours of use

Replace the oil filter, drain the old oil and put in fresh oil into your generator.


  1. Can I use low-quality synthetic oil on my Predator 3500?

Yes, you can. However, you will not get the best performance.

  1. What happens if I change generator oil regularly?

Your generator is able to maintain peak performance at all times.