When the power comes back on and you put your generator away for long-term storage it’s pretty easy to forget all about it until the next time your lights go out.
That might be a year or more. At that rate, there’s no guarantee that your generator will start up or even if it does that it will produce power for you.
It definitely pays to have a regular schedule where you routinely start up your generator for only 10 minutes or so just to ensure that everything is in working order for the next time that you need it. The last thing that you want is to find yourself needing to fix your generator in the dark and when your family is stressed that you can’t seem to get the lights back on.
All of this can be prevented with a routine test run of the generator every now and then.
A good practice is to run your generator every 1 to 2 months for 10 minutes at a time and place a decent load on it for a minute or so to ensure that the coils are still magnetized. Regularly scheduled test runs will ensure your generator is in working order when needed most and that problems are identified early.
Why Should a Generator be Routinely Started When Not in Use?
To answer the question bluntly, a generator is an engine and engines are designed to run — not sit.
You’ve probably heard that small planes don’t break down in flight but they surely break down when staked down next to the runway. A generator is the same way.
You’ve got two primary components to what we simply refer to as a “portable generator”. You have the engine and then you have the actual generator which is responsible for generating the power that you need to run your appliances.
The engine powers the generator and the generator powers your home.
Running them both will ensure that you keep them tuned and that you will identify problems early when you have time and the stress-free environment to fix them.
How much stress your generator is under when it’s not running is almost entirely dependent upon the way in which you store it. The type of gas, whether or not it was stabilized, whether or not you drained the carburetor, whether or not you have a lot of gas in your tank or a little, etc.
I’ll get to the best way to store your generator for maximum performance in just a bit.
Let’s talk about the generator for a moment, and by that, I mean the part of the unit that supplies the power to your home. The generator has lots of wire coils inside that need to maintain a certain magnetism in order to be excited enough to start the power generation process when you place a load on it.
Allowing the generator to sit idle for months or years on end increases the chance of these coils losing their magnetism and providing you with zero power during an outage.
The engine itself might still run perfectly but the generator will be goose egg. Your appliances will not power up when plugged in despite the purring engine.
In many cases, you can “flash” your generator to manually re-magnetize the coils with a simple corded drill. Generac has a Youtube video that you can check out below.
Running your generator every month or two and placing a load on it for a minute will keep these coils magnetized and primed for your next emergency.
As far as the engine, you have a lot of moving parts and different components that can all be affected by sitting idle for extended periods of time. Like I mentioned before, a lot of this depends on the state in which you last left it and how you powered it down.
The rubber seals on the pistons are not served well by being stuck in one position for months or years on end and you risk them becoming deformed or rotting from lack of lubrication.
Running your generator regularly will keep these rubber seals flexible and let them keep their lubrication and integrity.
The gasoline that you use is by far the most critical aspect of your storage endeavors. If you choose to keep gasoline in your generator year-round like I do, you had better be using gasoline that has been stabilized and that is ethanol free (the last part is my opinion).
Most generators will run just fine on regular unleaded gasoline with 10% ethanol. That isn’t my concern though. My concern is with how that gasoline reacts with the different components of the engine over months and years of storage.
From my experience with repairing small engines for friends and coworkers, the people who use regular unleaded (10% ethanol) see the most problems and it usually involves rotting or damaged rubber o-rings, water in the carburetor bowl, and rotting rubber float needle seats in the carburetor.
Can I definitively link ethanol-blended fuels with these rotten rubber parts? No. I’m a hobbyist and not a mechanical or chemical engineer. I’m just going with my gut, and you’ll find just as many people online who bash ethanol-blended fuels as those who defend them adamantly.
If you are going to store your generator with gasoline in it (either ethanol blend or ethanol-free), make sure that is stabilized (I prefer SeaFoam) and to keep the tank filled to minimize the amount of oxygen that can oxidize the fuel and to minimize the amount of condensation that can occur on the inside of the tank with increased humidity in the air.
Running your generator regularly will allow you to make sure that it idles well, revs up well when power is demanded, and that there are no stalling, surging, or backfiring issues, etc.
If there are issues like the ones mentioned above, they are usually related to the carburetor or spark plug from my experience. If it’s a carburetor issue then the reason why is almost always a fuel storage issue. Either the fuel is too old, untreated, has too much water from condensation in the tank, etc.
I have a step-by-step guide here on cleaning a generator’s carburetor with pictures.
The presence of rodents is another reason to start your generator regularly to ensure that they haven’t done any damage or built any nests around your engine. Mice will chew through wires, fuel lines, and build nests around your engine which will cause it to overheat from the insulation created by the nest.
They will also build nests around the air filter/intake area which will not allow your generator to start or if it does it will run very rough.
I keep several mouse traps around my generators at all times.
If your generator has an electric start, a regular test run is also great to make sure that it still works and that your battery is in good working order.
If you typically use the electric start and you are able to physically start the generator with the recoil cord, then I recommend doing both just to cover the functionality of each. If one fails you want to know that the other will work.
Setting a Schedule for Running your Portable Generator
I find it easiest to set a calendar reminder on my phone for the entire year.
I set a monthly reminder on my phone on my typical day off and I make a point to do the 10-minute test run as I eat lunch or drink a cup of coffee.
I do my tests monthly, but I’m sure you’d be fine if you did them every 8 weeks and sometimes that’s what happens with me when life gets in the way.
Even if you fired it up quarterly, I’m sure you’d be far ahead of a large percentage of generator owners!
The best part about doing regular tests is that your generator will generally start on the first pull of the cord. I know that if mine takes more than 2 pulls that I probably have a problem and that I have done something wrong (or something is going bad).
How to Test Run your Generator and Properly Shut it Down for Storage
Testing your Generator:
Each time that you test run your generator the first thing you should before you even start the engine is to do is a visual inspection around the generator to make sure that you don’t see any fluid leaks either from oil or gasoline.
After that do a visual inspection of the unit to make sure you don’t see any mouse nests built around the engine anywhere.
Next, bring your generator outside, turn the fuel valve on from the off position, turn the choke on and prime your carburetor if required (typically inverter generators, from my experience).
After that, pull the recoil cord or use the electric start (but I always recommend doing both at some point during your test run to make sure that both options work in case one fails when you need it most).
If you cannot get your generator to start, I have an article dedicated to possible causes, symptoms, and fixes.
Once the generator fires up, gradually take the choke off until it’s all the way open and let your generator run for around 10 minutes at idle. Listen out for any abnormalities as you enjoy being outside for a few minutes sipping some coffee.
Now, after it has warmed up and you haven’t noticed any problems whatsoever, you should move on to the next step where you will put a load on the generator to make sure that it successfully supplies electricity and that the coils are still magnetized.
I like to plug in a power tool and I usually just use my circular saw which requires a high start-up voltage and will definitely wake the generator up for a good test. Since I run regular test runs with my generator I don’t have any issues getting the circular saw to turn on.
I generally hold the trigger down on the circular saw for about 1 minute (pointed in a safe direction of course) and then I turn it off. I’ll fire it on and off a few more times to make sure that the generator responds properly.
Proper Shut-Down Procedure for Your Generator
Once that’s done I unplug the circular saw, turn off the AC power switch, and turn off the fuel shutoff valve for the engine. This cuts off the fuel running from the gas tank to the carburetor and now the engine will burn only the remaining gas that is still in the carburetor.
Depending on the size of the carburetor your engine might run for a little bit until its inevitable sputtering session and will finally stall. Once it runs out of fuel to burn, the carburetor bowl will be mostly empty of fuel which will allow the small jets and orifices to not become gummed up by any gas that may happen at go bad (especially if you didn’t stabilize it).
It also allows the float needle to drop from the rubber seat that it presses into when the carburetor is full of gas. If left in that position, it can become deformed over time or even stick which will either cause your generator to flood (if the seat is deformed) or not start due to an absence of fuel (if it sticks).
Wheel or carry your generator back into the garage and top off the fuel if necessary to the maximum fill line. Do not fill the gas tank all the way to the very top as the gasoline does need room for expansion as the unit gets hot.
After your generator cools off you can put a proper cover over your generator that is specifically made for the purpose. I do not recommend putting anything plastic that isn’t breathable over your generator as this will invite condensation and moisture around your unit which can ruin the electronics and lead to other rusty parts. I also steer clear of using an old blanket or sheet in case removing it causes static electricity. Since I store my unit with gas I don’t want to take a chance with a vapor leak.
If you store your generator without fuel, just go ahead and shut off the fuel valve the same way when running. It will stall and your carburetor will be mostly free of gasoline. After that, you can locate where the fuel line supplies the carburetor and pinch off the line with a pair of vice grips a few inches away.
When that’s done, use pliers to remove the hose clamp and back the fuel line off of the carburetor as gently as possible with a flathead screwdriver. Keep the line elevated as you carefully bring it down to a proper container for holding your fuel. Once the line is in the container, open the fuel shutoff valve to allow the remainder of the gasoline to flow from the tank into the container.
When done, reattach the fuel line and slide down the hose clamp to secure it in place.
You can also use a 10mm wrench or socket to remove the bowl of the carburetor and drain any residual gasoline if you are so inclined.
Take caution with accessing the fuel line to the carburetor if you do this immediately after doing a test run since you might be working next to the exhaust area for draining the fuel and you don’t want to get burned.