10 Handy Portable Generator Repair Tips to Improve Performance

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One thing that most serious preppers have in common is that we all own at least one portable backup generator. 

While many preppers actually own generators, if I was a betting woman, I would say that not many people have very much real-life experience in using them.

This was very true for me before our family moved off the grid to live in the mountains of southern Oregon. Those years taught us so much and I’m happy to be able to share some of our lessons with you.

I’m writing this article from the unique perspective of being a person whose only form of electricity for over eight years was provided by generators. On a typical day, we ran our generator for about 10 hours which means that over the years we put over 31,000 hours on them!

I would wager that most preppers haven’t even run their generators for 100 hours. Why is this important, you might ask?

The reason it’s important is that my husband and I have a ton of experience using portable backup generators and with that experience comes a lot of knowledge that I can share with those who might just be getting into prepping as well as those who are already experienced preppers.

Our experience has taught us that there are really only a few things that will typically go wrong with a generator if you take the time to perform routine generator maintenance. Having said that, when you use power equipment a lot, you will experience breakdowns and you will have to make repairs. In this article, I’ll be drawing upon the experience that we have acquired with the intention of helping people who aren’t as familiar with emergency backup generators tackle the most common types of repairs that they might encounter.

In the interest of full disclosure, my husband coached me as I was writing this article since he is the one who actually does the repairs on ours. One other thing that I highly suggest is to arm yourself with the proper service manual for your particular engine before you attempt any of the following repairs.

Before we get started, let me give you my most valuable tip. Take lots of pictures with your digital camera or phone before you disassemble any parts. Having access to these photos has saved our bacon MANY TIMES when it came time to reassemble the parts!

Warning: Some of the procedures outlined in this article involve working with gasoline, carburettor cleaner, and/or starting fluid. All of these items are HIGHLY FLAMMABLE. Never perform any of these procedures around an open flame or any other possible ignition source!

10 Portable Generator Repair Tips That Many People Can Handle


If you’re having a difficult time starting your generator or if it’s just not running right, there are a few things you should probably check. Keep in mind that in order for the engine to run, it needs three things. These things are fuel, spark, and oxygen. There is a fourth and that is “compression” but in most cases, the three things that I’ve referred to will be the culprit to a poor running engine.

1. Check for Fuel Delivery Problems: The engine on your generator is going to have a carburettor and its sole purpose is to mix the gasoline from your gas tank with air at the proper ratio for combustion to occur in your engine. If your generator is difficult to start or if it runs really rough you may have a fuel delivery problem. You really need to make sure that your carburettor is actually getting fuel before you proceed. Note that on some high-end generators, they may be equipped with a fuel pump. Refer to your service manual for the proper way to test your fuel pump if you have one.
One way that some mechanics test to see if the problem is related to inadequate fuel delivery is to remove the air filter and spray a tiny amount of starting fluid directly into the carburettor. Then they try to start the engine. If it starts but quickly stalls, the problem is likely related to fuel delivery. Note that a little goes a long way when it comes to using starting fluid for this type of a test. The last thing you want to do is spray too much into the carburettor and end up starting a fire. If you choose to use this test, you’re doing so at your own risk. Don’t say that I didn’t warn you! Also, I’ve heard that you shouldn’t use this test on diesel engines.

2. Check the Gas Vent Hole: There’s usually a tiny hole or valve somewhere on the gas cap that is designed to allow fuel to flow from the tank and into the carburettor. If this vent hole gets plugged up, no fuel will be able to flow into the carburettor and your engine won’t start. If it’s only partially clogged, the engine may start and either run poorly or stall after a few minutes. The solution to this problem is simply clearing the vent hole with a small piece of wire or a short blast of compressed air.

3. Check the Fuel Lines: If your fuel lines are plugged up with debris, cracked, or leaking, don’t bother trying to repair them; simply replace them. You can buy the correct size of fuel line at any auto parts store. They sell it by the foot and it’s quite inexpensive.
10 Handy Portable Generator Repair Tips to Improve Performance
4. Inspect the Fuel Filter: Some, but not all, generators have an in-line clear plastic fuel filter. These filters are designed to keep dirt and debris that might be in the gasoline from entering into your carburettor. If yours is clogged, the carburettor will be starved from getting fuel which could prevent the engine from starting. If it does happen to start, it may run rough and/or stall shortly thereafter. The easiest way to check to see if the filter is clogged is to remove the fuel line at the point where it is attached to the carburettor. Make sure that you hold the fuel line over a container to catch any gas that leaks. Pay special attention as you watch to see if any gas is actually passing through the filter. If gas doesn’t drain out of the fuel line and into your container, my recommendation would be to replace the fuel filter.

This is a very easy job and the fuel filters are only a few dollars each. There will be a tiny hose clamp on each end of the filter. All you have to do is remove the clamps, pull the fuel lines off of the old filter, put the fuel lines on the new filter, and reattach the hose clamps. Make sure that you don’t put the filter in backwards either. They are designed for fuel to flow in one direction only and that is from the gas tank to the carburettor.

5. Cleaning the Carburetor: If your carburettor is actually getting fuel but the engine is running rough, this is usually caused by people leaving old untreated gasoline in their tanks and not starting the engine for quite some time. The first thing that you might try doing is draining all of the old gas and replacing it with fresh gas. You’ll also have to drain the old gas from the float bowl on the bottom of the carburettor. If this doesn’t work, you’re going to need to clean the carburettor. In some very rare cases, you can spray carburettor cleaner into the orifices and jets without removing it from the engine but in most cases you’ll need to remove the carburettor to clean it properly. Sometimes an engine that has a dirty carburettor will start and run if you leave it in the “full choke” position but as soon as you move the choke lever to the off position, the engine will sputter or shut off.

The basic thing to remember about this is that if a carburettor is the cause of an engine not running properly, it’s usually not an adjustment problem but rather a matter of the carburettor being dirty. When gasoline that hasn’t been treated with a fuel stabilizer sits in a carburettor for a long period of time, it’s going to do two things. It will accumulate water and the gas will go stale and turn into a thick varnish-like substance that will clog the tiny orifices in the carburettor. Our experience has been that when a carburettor is the cause of a rough running generator engine, it’s almost always because it is dirty and the orifices in it are clogged. Performing a thorough cleaning has usually solved this problem for us.

4-3-15 Update: I just received a comment on this article from someone who was a generator repair tech for 15 years and he stated that most of the generator problems that he dealt with were the result of people leaving old, untreated gas in the carburettor for an extended period of time. After you read this article, be sure to scroll down and read his comment.

One very important thing that I should point out about cleaning carburettors is to resist the urge to clean the tiny orifices by inserting wires or anything that is metal into them. Carburettors are very delicate instruments and if you scratch or deform the shape of the orifice it will never run properly again.

Since carburettors are such sensitive devices. Be extremely careful when it comes to turning any of the adjustment screws. If you do turn them and you don’t get them returned to the exact same spot, your generator is not going to run right, if at all.

You can find lots of helpful videos on YouTube that will teach you how to clean a carburettor. My husband has done this procedure many times and he’s learned some hard lessons along the way. The main one being that carburettor parts are very small and easy to lose so always work on a surface that will catch any small parts should you happen to drop them. I can’t tell you how many times he has dropped the tiny parts from a carburettor and lost them in our gravel driveway.

6. Make Sure You Have a Spark: If your generator is difficult to start or if it’s running rough, the first thing you should probably check is to make sure the spark plug looks good. The appearance of the spark plug can give you a good indication about how your generator is actually running. If the electrode is caked with an oily thick sludge, your generator has probably been running very “rich” meaning that it’s been getting too much fuel and not enough oxygen. On the other end of the spectrum, a carburettor that’s not delivering enough gasoline but it’s providing too much air will result in a spark plug that is light tan or even white. This is referred to as running too “lean”.

I usually don’t recommend that anyone make adjustments on their carburettor to remedy this type of a problem as this is usually a task reserved for more experienced mechanics but there are some things that you can do if you inspect your spark plug and discover that it doesn’t look right.

The first bit of advice I have for you is to replace your spark plug with a new plug instead of trying to clean the old one. Spark plugs are very inexpensive and there may be hairline cracks in the insulator that you can’t see with the naked eye that is causing them to malfunction. The basic take away here is that if your spark plug looks bad, just throw it away and replace it. One important thing to remember is that when you replace your spark plug, you’ll need to make sure that you use a spark plug gapping tool to adjust the gap between the ground electrode and the centre electrode to the manufacturer’s recommended settings.

The other thing to keep in mind is that if your plug isn’t actually producing a spark, your engine won’t start no matter how hard you pull on the cord. If you don’t know how to check to see if your engine has spark, there are plenty of YouTube videos that you can watch to learn how.

7. Make Sure Your Engine is Getting Oxygen: As I mentioned above, the sole purpose of the carburettor is to mix the gasoline with air and deliver it into the engine in the form of a fine flammable mist. Any air that enters into the carburettor has to pass through an air filter first. The purpose of the air filter is to prevent dust and debris from getting into the carburettor or the combustion chamber of the engine. When the air filter is clean, it will function properly and do exactly what it is intended to do. If the air filter is old or you’ve been running your generator in a very dusty environment, the filter will clog and restrict the amount of air that is able to pass through it and enter into the carburettor. This will result in your carburettor spraying too much gasoline into the combustion chamber and not enough air. Some symptoms of this are a rough running engine or an engine that will run for a while and then stall because it gets flooded with too much gasoline.

Some people try to extend the life of their air filters by removing them and tapping them against a hard surface to knock any dust and debris out of them. Whatever you do, resist the urge to use compressed air to blow the dirt out of an air filter. This will usually result in the tiny openings of the air filter becoming enlarged which will prevent it from doing its job of actually blocking dirt and dust from passing through it.

Our experience has been that if our air filter looks fairly clean, tapping it firmly against a workbench or other solid surface will remove some of the dust. In other cases, the best option is to simply replace it with a new filter.

I should also point out that there are a couple of different types of air filters that you might have on your generator. Our large 5,500 watt Generac uses a paper air filter but our smaller Honda EU2000i uses a foam air filter that is serviceable by the owner. You can actually clean this type of an air filter when it gets dirty and it will work as good as new once you reinstall it. Be sure to follow the manufacturer’s instructions precisely about how to properly clean your particular generator’s air filter.

8. Replace a Broken Pull Cord: In all the years that we’ve been using generators, we’ve broken the pull cords about four times. It’s not incredibly difficult to replace the cord if you happen to break it. The tricky part is to make sure that you wind the spring up all the way before you wrap the new cord around the starter mechanism. If you don’t, the spring won’t be able to pull the cord back inside the housing and you won’t be able to start your generator at all.

9. Test the Electric Starting System: Your generator may be equipped with an electric starter. If you turn the key or press the button and nothing happens, there are a few things that you can check. The first is to make sure that your battery isn’t dead. You can use a simple multimeter that you can buy for around $20 at most auto part stores to find out what the voltage of your battery is. A brand new 12-volt battery should read somewhere in the neighbourhood of 12.6 to 12.7 volts when it’s fully charged. If you test the battery with a multimeter and it reads lower than 12 volts, connect it to a charger to see if you can recharge it. If you’ve made the mistake of neglecting your battery and leaving it in a state of discharge for many months, you probably won’t be able to charge the battery and your only option will be to replace it.

If your multimeter shows that the battery is charged but the starter still doesn’t turn over, the first thing I would do is check for any fuses that might be blown. If you have a fuse that has blown, simply replacing it will usually fix your problem. Make sure you replace it with the exact same type of fuse that has the same amp rating. If the fuse in your generator was rated at 20 amps, don’t try sticking a 30 amp fuse in it because that’s the only one that you might have on hand. There is a reason that it was equipped with a fuse of a particular size and that reason is so that the fuse will blow before any sensitive electronic components will be damaged. If you put an oversized fuse in it, instead of the fuse blowing, you’ll fry the electrical components which will be a more costly repair.
If you don’t find a blown fuse, the next thing I would check is to make sure there’s no corrosion on the battery terminals and that the connections are actually tight on the battery. Believe it or not, it’s possible for corrosion to accumulate between the cables and the battery even though they may “appear” to be clean and corrosion free. Whenever we’ve had a problem with a fully charged battery not starting the engine, we remove the battery terminals and clean them with a wire brush so that the surfaces are nice and shiny. In many cases after cleaning and reattaching them, the engine started right up.

If you’ve tried all these things and the starter still won’t work, there’s an old mechanics trick that you might try. Gently tap on the starter housing with the plastic handle of a screwdriver several times. If corrosion has built up inside the starter that is preventing it from turning, this will sometimes break it free and get it working again.
There is one more component to an electric starting system that could go bad and that is a part called a “solenoid”. Refer to your service manual about how to test this device. Unfortunately, it’s not one of those things that you can repair so if it’s bad, you’ll simply have to replace it.

10. Replace the Breakers: If your engine starts and runs properly but it doesn’t put out any electricity, you can sometimes fix this problem by replacing the breakers. We’ve never had this problem with our Honda generators but we’ve had it happen twice with our Generac. It’s an easy fix. The main thing to know about doing this is to only replace the breakers with the manufacturer’s approved replacement part. Also, take pictures and mark the wires with masking tape so you’ll be sure to put them back in exactly the same place on the new part as they were when they were removed from the old part.
Bonus Tip!

Many engines are equipped with a low oil shut off feature. This feature is designed to disable the engine when the oil level is too low to adequately lubricate the moving parts. If your engine won’t start or it starts and then stalls, check the oil level to make sure it is at the recommended level.

Share Your Thoughts! I’d love to hear from you if you found this article helpful in any way. Please take a brief minute and leave me a comment in the box below!
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Synergy Solar Zimbabwe is looking forward to your call or WhatsApp Message.

Please feel free to leave a message on our WhatApp number or alternatively please call us and we will be able to help you straight away. If you would prefer, send us an email with your details and an outline of your enquiry and we will be pleased to come back to you. We respond to all enquiries usually within 24 hours, but guarantee within 48 hours.

Our Contact Numbers Are: +263 77 389 8979 and +263 71 961 3479.