How to Break In a Portable Generator? (Correct Procedure)

portable generator break in procedure

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Breaking in a generator is one thing that is often ignored by RV owners after buying a new unit.

It should be the first thing to do right after unboxing your new generator to ensure long working life and peak performance.

But, how do you break in your generator properly?

To break in your generator, run it for an hour without load and drain the engine oil. Pour in new engine oil and run it for one more hour, but this time with a small load on it.

Generator break-in is an easy process if you follow the right steps.

In this post, we’ll dive deeper into the correct procedure to break in your new portable generator.

But first, let’s start by looking at the meaning of breaking in a generator.

What does Breaking In a Generator Mean?

Breaking in a generator simply means running the unit following a specific break-in procedure while changing the engine oil a few times in between.

The break-in process smoothens the cylinder walls of the engine, making a perfect fit while reducing wear and tear. While the cylinder walls smoothen out, tiny metal particles will be shaved off which are also removed during a break-in process.

It also lubricates the moving parts inside the engine which reduces friction eliminating the possibility of internal parts breaking, while preventing a dry start.

Is it Necessary to Break In a New Generator?

Breaking in your new generator is the only way to increase its lifespan and performance. Using a generator without breaking it first will have detrimental effects on its performance and working life.

Generators out of the box come with completely dry engines. The break-in process of the generator makes sure the moving parts are lubricated properly before running, preventing a hard start. Engine hard start is one of the biggest reasons why new engines fail so soon.

The break-in process flattens out uneven surfaces inside the cylinder as the piston moves up and down. This creates tiny metal shaving that when left in the engine can damage it. The break-in process will also help remove these metal particles from the engine.

How do you Properly Break In a Generator?

Generator break-in may sound intimidating at first, but I assure you it is the easiest maintenance you’ll ever perform. However, there are procedures you have to follow to make sure the break-in is done correctly.

Follow this step-by-step guide to properly break in your generator and ensure its long working life.

However, before we start breaking in your portable generator, here are a few things you’ll need to have in hand to make the process smooth.

  1. An oil conditioner is used to lubricate the cylinder walls and pistons that prevent a hard start. The Lucas 10001 is thick petroleum bases lubricant that covers the cylinder walls and the pistons to reduce friction in the initial run.
  2. Though most portable generator brands include a motor oil that is to be used during the break-in process, you can purchase one if yours doesn’t come with one. Depending on your manufacturer’s recommendation, you will need either a 5W30 or a 10W30 motor oil.
  3. A wrench to remove the spark plug is also included with some brands, but you can get this wrench set if yours doesn’t come with one pre-packaged.
  4. Spark plugs ignite the fuel inside the engine, and having a few spare at hand is always reassuring. The NGK 7131 BPR6ES is my recommendation.
  5. A magnetic dipstick helps collect the metal shaving effectively that is created due to wear and tear as the motor runs. The WEN 55201 is what I like.
  6. Lastly, you need fresh fuel, preferably non-ethanol blended or the highest octane rating you can find. Moreover, a good quality fuel stabilizer like the one from STA-BIL is always a good idea to have.

Now with the generator break-in process.

1. Unbox your Portable Generator

Carefully unbox your generator once you bring your generator home or get the delivery. Check all the items that are included with the generator and get the ones that are not from the list above.

Once out of the box, check for any physical damages or worn-out wires. If your generator has an automatic start, connect the battery following the correct procedure stated in the user’s manual.

2. Lubricate the Cylinder

Remove the service panel of your generator and with the right size wrench from the wrench set, loosen the spark plug and remove it. Pour a few drops of oil conditioner (Lucas 10001) through the spark plug chamber.

You can use a funnel if the spark plug chamber is not easily reachable. Wait for a few minutes giving the oil conditioner some time to drip off the funnel.

Now, pull the generators pull start cord a few times, very slowly. Make sure you don’t pull the starting cord before lubricating, as it will damage the cylinder.

Your cylinder wall is properly lubricated once the pull cord feels smooth enough. You can now replace the spark plug the same way you removed it.

3. Add Engine Oil

Add a squirt of the Lucas 10001 oil conditioner into the crankcase, followed by the engine oil. You can use the engine oil that came with the generator or get a 5W30 or a 10W30 depending on what your manufacturer recommends.

Refer to your generator’s user manual to find how much oil the engine takes and the recommended fill level. Using a funnel, fill up the oil and wipe off any oil drip-offs using a clean cloth or a kitchen towel.

4. Add Fuel into your Generators Fuel Tank

Fill up your generator with freshly purchased gasoline, preferably non-ethanol blended or the highest octane grade you can find. Make sure to fill up the tank completely so that it lasts the whole break-in period.

At this point, add the right amount of STA-BIL fuel stabilizer. Though adding too much fuel stabilizer won’t hurt, following the manufacturer’s recommendation is what I suggest.

Take your portable generator out in a well-ventilated place away from your home before you start the engine. This eliminates the risk of carbon monoxide poisoning and fire hazards. Your generator needs to be at least 20-feet away from your home.

If your fuel cap has a vent, put it in the on position, and the engine switch to the on position. With the choke open, wank the pull start cord a few times until your generator starts.

Note: You may see white smoke for a few seconds as the engine starts. However, you don’t have to worry as it is the oil conditioner that you added to the spark plug chamber that is burning away.

5. The First Run

As the unit starts running, give it a few minutes to settle down and turn on the economy mode, allowing it to run at its lowest speed. During the first run, it is important to let the generator run at the lowest speed without any load on it.

The initial run will last up to an hour, and you should be around to detect any abnormalities.

6. Change the Engine Oil

Once you reach the one-hour mark, follow the correct procedure to turn off the generator for an oil change. However, make sure not to drain the oil immediately after turning off the machine as the engine and oil is hot and can burn you.

Once the unit cools down, drain the motor oil from the generator into a container for disposal. Draining the oil at this stage gets rid of the majority of the metal shaving and particles that the engine created.

Now, remove the magnetic dipstick and wipe off all the metal flakes using a clean cloth or kitchen towel.

Next, add a squirt of oil conditioner in the crankcase and refill the motor oil to get your generator ready for the second run. Moreover, check the fuel level and refill if necessary.

7. The Second Run

Now, start the generator back up again and let it run for one more hour, without any load on it. The second run will help get rid of any leftover metal particles inside the engine.

Drain the engine oil after the second run is complete. At this point, the engine oil should be a lot cleaner than it was after the first run.

8. The Load Run

Once the unit is ready, fire it back up again and add load to it. Many recommend a load of about 500 watts, but I like to add a load that is equal to ⅓ of the rated wattage of the generator.

Let the generator run for one more hour with the load connected. Once the generator crosses its 3-hours runtime mark, your generator break-in is complete.

Now, you can change the motor oil and use it normally to power your RV at the campsite without any issue.


Generator break-in is essential to make sure its longevity and peak performance. Without breaking in your generator, you’ll make the unit unusable in no time.

Breaking in a generator is the easiest maintenance procedure that doesn’t cost a lot of time and money. However, you need to follow the proper procedures to make sure it is done correctly.