How Portable Generators Work

When handled properly, your portable generator isn’t just an investment. It can be a lifesaver. But have you ever stopped to consider how they actually work?

It isn’t quite rocket science. It doesn’t require extensive technical knowledge. And while you may owe it to yourself to know the basic nuts and bolts of how to use one properly, the mechanics of just how portable generators work can sometimes seem like a mystery to even the most savvy of customers.


Your portable generator needs regular maintenance. And ensuring that the engine is clean and free of debris is essential for a generator to operate smoothly.  Before you run it, check to see that there are no loose nuts or bolts⁠—fasten any, if need be.

Typically, generators will operate on a 4 cycle engine, which is just about enough to run at 36000 RPMs for 120 volts of continuous electricity. Frequently, you’ll find the following components on a single portable generator unit:

  • Internal combustion engine
  • Alternator
  • Starter
  • Fuel tank
  • Power outlet

Portable Generator Heads

Portable generator heads are what provides electricity to an outlet. While the engine provides power to a generator head, it’s actually powered by fuel, which can be diesel, propane or natural gas. Once the fuel is added, the generator head will strike a shaft, which is then regulated by a running speed governor to ensure the consistency of the spin. If you have an electrical start, make certain that the battery is completely charged prior to operating a generator.

Cooling Systems

Even though your portable generator head is fuel powered, it’s the mechanical energy which converts it into electricity. And to avoid overheating, it needs a cooling system in place along with lubrication. The generator actually moves a magnet which helps to create an electrical current. The pressure involved measures the voltage in watts, amps and (of course) volts.

If you’re repairing a portable generator yourself, allow it to cool off entirely before any maintenance you perform. If fuel accidentally falls on any part of the engine while it’s still hot, it can spark a fire. You also might want to consider investing in a portable generator cover to minimize exposure to the elements.


While the type of electricity for a generator can vary depending on its brand and make, keep in mind that it’s also generating gas emissions—in particular, carbon monoxide. Fatal conditions have occurred from indoor use of portable generators, including both fire and carbon monoxide poisoning.

There’s an even greater risk of causing a fire by exceeding a portable generator’s power rating. Plugging a generator into a standard wall outlet will both short circuit your home and send a fatal current of electrical energy through the cord.


Don’t try to operate a portable generator with a torn or frayed cord. At best, it won’t operate. At worst, you’ll face a potentially lethal electrical shock. When in doubt, use a grounding pin to help keep the cord safe. Even a 30 amp generator will need to cord that’s at least 10 amps—preferably higher. Cable covers can also be an excellent defense from potential damage to a cord.


One of the more common complaints about portable generators is that they’re not always fuel efficient—particularly if you’re not using a heavy load for a long time. But there’s also an environmental risk of polluting the ground if they’re not used at full fueling capacity, even if that ground is simply your garage floor. While constantly refueling a generator can seem expensive, in the long run it’s worth it. Always try to ensure you’re operating with a full or near full tank. The average fuel tank will keep anywhere from three to six gallons at full capacity, so it’s not the most convenient option in the world. But it is a sensible way to optimize the life of your generator.

Running And Standby Power

Another common drawback in many portable generators is in the initial surge of power before they’re fully up and running. While this is never convenient when you’re faced with an emergency, one way to avoid this is through continuous usage. Any large mechanical device takes a while to break in, so don’t be disappointed by what seems to be a limited running power at first.

Short And Long Term Storage

To actually get the most out of your portable generator, clean any debris after each use. Make certain it’s easily accessible in a garage or basement for when you need it the most. Longer term storage over a space of several months can be optimized by keeping the tank full and adding a gasoline stabilizer to reduce viscosity.

Power Limitations

It’s not likely you’re going to need to power the entirety of your home during an outage; just the essential necessities. If you need to generate continuous power for multiple devices in your home, you should probably decide on a model that has a higher wattage—in particular, surge watts if you need to power up quickly.

Is a portable generator cheaper compared to traditional standby models or extensive electrical repair? Absolutely. But with any mechanical device, there’s always going to be both advantages and disadvantages. But it’s safe to say that a power outage has a much higher disadvantage than anything else.

And I think most of you will agree with me.

If you need a convenient and reliable engine maintenance and service in the greater Reno area, look no further than Greg’s Small Engine Repair. We don’t just save you time. We give you practical advice you can use. Visit us today at Greg’s Small Engines.