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If you own a Generac GP5500 generator, you know how reliable and powerful it is. It can provide up to 5500 running watts and 6875 starting watts of electricity for your home, RV, or job site.
However, like any other generator, it can sometimes fail to start or run properly. This can be frustrating and inconvenient, especially when you need power urgently.
Fortunately, there are some common reasons why your Generac GP5500 generator won’t start and some simple solutions you can try to fix.
Some of the common reasons a Generac GP5500 won’t start include a bad spark plug, valve clearance, bad or empty fuel, oil level and quality, recoil starter, ignition coil, and many more.
So, in this blog post, I show you how to troubleshoot and resolve most of the starting problems with your Generac GP5500 generator.
But, before we begin, make sure you have the following tools and materials ready:
- A screwdriver
- A spark plug wrench
- A fuel siphon pump
- A multimeter
- Fresh gasoline
- A fuel additive
- A clean rag
- A new spark plug (optional)
- A new air filter (optional)
- A new fuel filter (optional)
RECOMMENDED READ:- Generator Won’t Start After Running Out of Gas Here’s What to Do
Here is How to Fix a Generac GP5500 generator that won’t start
1. Empty or bad fuel
One of the most obvious reasons why your Generac GP5500 generator won’t start is that it has no fuel or that the fuel is old and degraded. The Generac GP5500 generator has a small fuel tank that can run out quickly if you forget to refill it or check the fuel gauge. Moreover, gasoline can also deteriorate over time and lose its effectiveness, especially if it contains ethanol, which can attract moisture and form a varnish that can clog the fuel system.
To fix this problem, you need to add fresh gasoline to the fuel tank and make sure it has at least an 87-octane rating and no more than 10% ethanol content. If possible, use ethanol-free fuel for better performance and longer shelf life. You should also use a fuel stabilizer if you plan to store the fuel for more than 30 days, as it can prevent the fuel from breaking down and forming deposits. Additionally, you should store the fuel in an approved container away from moisture and heat sources.
ALSO READ:- Can You Dump Old Gas on the Ground?
2. Plugged or Clogged Fuel Filter or Line
Another possible reason why your Generac GP5500 generator won’t start is that the fuel filter or line is plugged or clogged with dirt, debris, or varnish. The fuel filter is a small component that filters out any impurities from the fuel before it reaches the carburetor. The fuel line is a rubber hose that connects the fuel tank to the carburetor. Both of these parts can get blocked by foreign particles or gummed up by old fuel, preventing the proper flow of fuel to the engine.
To fix this problem, you need to inspect, clean, or replace the fuel filter and line. You can find the fuel filter near the fuel tank or inside it, depending on the model of your generator. You can remove it by disconnecting the clamps that hold it in place and then blowing through it to see if it is clear. If it is dirty or clogged, you can either clean it with compressed air or a soft brush or replace it with a new one.
You can also check the fuel line for any cracks, leaks, or kinks that might restrict the fuel flow. If the line is damaged or clogged, you can either cut off the bad section and reconnect it with a hose clamp or replace it with a new one. You can also clean the inside of the fuel tank with a rag or a brush to remove any dirt or sediment that might have accumulated over time. After cleaning or replacing the fuel filter and line, you should prime the fuel system by pressing the primer bulb several times until you see fuel flowing through the line. This will ensure that there is enough fuel in the carburetor for the engine to start.
FOR MORE INFORMATION ON HOW TO CLEAN FUEL FILTER READ:- How to Clean Generator Fuel Filter in 8 Simple Ways
3. Spark plug
The spark plug is a small device that creates a spark to ignite the air-fuel mixture in the combustion chamber. If the spark plug is defective, worn out, or fouled, it can prevent the engine from starting or running smoothly. To fix this, you should inspect the spark plug and clean or replace it if necessary.
To access the spark plug, you will need to remove the spark plug wire and boot from the spark plug. Then, you can use a spark plug wrench to unscrew and remove the spark plug from the cylinder head. You can inspect the spark plug for any signs of wear or damage, such as cracks, burns, erosion, or carbon buildup.
If the spark plug is dirty, you can try to clean it by gently scraping off any deposits with a wire brush or a knife. You can also use a gap tool to check and adjust the gap between the electrodes according to the specifications in your owner’s manual. If the spark plug is damaged or too worn to be cleaned, you should replace it with a new one. Make sure you install the new spark plug with the correct torque and reconnect the spark plug wire securely.
RECOMMENDED READ:- FAQs: Why Do New Spark Plugs Turn Black? (Answered)
4. Oil Level and Quality
Another reason why your Generac GP5500 generator won’t start is that it has low or dirty oil in the crankcase. The generator has a low oil sensor that shuts off the engine if the oil level drops below a certain point to prevent damage. To fix this, you should check the oil level and quality and add or change the oil if necessary.
To check the oil level, you will need to locate the oil dipstick on the side of the engine. You should unscrew and remove the dipstick, then wipe it clean with a rag. Then, you should insert the dipstick back into the oil filler tube and pull it out again. You should check the oil level on the dipstick and make sure it is between the upper and lower marks.
If the oil level is low, you should add more oil of the same type and grade as recommended by Generac. You should use a funnel to pour oil into the oil filler tube until it reaches the upper mark on the dipstick. You should avoid overfilling the crankcase, as it can cause oil leaks or engine damage.
If the oil level is okay but the oil is dirty or contaminated, you should change the oil and the oil filter. To do this, you will need to warm up the engine for a few minutes and then turn it off. You should place a drain pan under the oil drain plug and remove it with a wrench. You should let the oil drain completely and then reinstall the drain plug.
Finally, you should refill the crankcase with fresh oil of the same type and grade as recommended by Generac. You should use a funnel to pour oil into the oil filler tube until it reaches the upper mark on the dipstick. You should start the engine and let it run for a few minutes to circulate the oil. You should check for any leaks or signs of trouble.
RECOMMENDED READ:- How to Fix a Generator Oil Leak in 7 Easy Steps
5. Ignition Coil
The ignition coil is an electrical component that generates a high voltage to fire the spark plug. If the ignition coil is faulty, it can fail to produce enough voltage or send it at the wrong time, resulting in a weak or no spark at all. To fix this, you should test the ignition coil and replace it if necessary.
To check the ignition coil, locate it on the side of the engine and disconnect the wire that connects to the spark plug. Then use a multimeter to measure the resistance between the two terminals of the coil. The resistance should be between 0.4 and 0.6 ohms. If the resistance is out of range, replace the coil with a new one.
To replace the ignition coil, you will need to remove the engine cover and the air filter assembly. Then, you should disconnect the wires from the ignition coil and remove the mounting bolts. You should carefully lift the ignition coil off the engine and install the new one in its place. You should secure the new ignition coil with the mounting bolts and reconnect the wires. You should also reinstall the air filter assembly and the engine cover.
6. Recoil Starter
If the recoil starter is broken, jammed, or worn out, it can prevent you from starting the generator. To fix this, you should check or replace the recoil starter if necessary.
To check the recoil starter, you will need to remove the engine cover and the air filter assembly. Then, you should pull the starter cord and observe how it behaves. If the cord does not retract or comes out too easily, it means that the recoil spring is damaged or loose. If the cord does not engage or slips, it means that the starter pawls or dogs are broken or worn out.
If the recoil starter is defective, you will need to replace it with a new one. To do this, you will need to remove the four bolts that hold the recoil starter to the engine. Then, you should carefully lift the recoil starter off the engine and install the new one in its place. You should secure the new recoil starter with the four bolts and reinstall the air filter assembly and the engine cover.
7. Fuel Valve
Another reason why your Generac GP5500 generator won’t start is that it has a closed or clogged fuel valve or filter. The fuel valve is a switch that controls the flow of fuel from the tank to the carburetor. The fuel filter is a device that filters out dirt and debris from the fuel before it reaches the carburetor.
To check the fuel valve, locate it on the side of the tank and make sure it is in the ON position. If it is in the OFF position, turn it to ON and try to start the generator again.
8. The carburetor
Another common cause of a generator not starting is a dirty or clogged carburetor or air filter. The carburetor is responsible for mixing air and fuel in the right proportion for combustion. The air filter is responsible for filtering out dust and debris from entering the carburetor and engine. If either of these components is dirty or clogged, it can affect the performance of your generator.
To check and clean your carburetor and air filter, follow these steps:
- Turn off your generator and let it cool down completely.
- Remove your air filter cover and take out your air filter element.
- Inspect your air filter for any signs of dirt or damage. If your air filter is dirty, clean it with warm water and mild soap. Rinse it thoroughly and let it dry completely before reinstalling it. If your air filter is damaged, replace it with a new one that fits your generator model.
- Remove your carburetor from your engine by disconnecting the fuel line, throttle linkage, and choke lever.
- Inspect your carburetor for any signs of dirt or debris inside the bowl or jets. If your carburetor is dirty, spray it with carburetor cleaner and use a small brush or wire to clean the jets and passages. Be careful not to damage any parts or lose any springs or gaskets. If your carburetor is damaged, replace it with a new one that fits your generator model.
- Reinstall your carburetor and reconnect the fuel line, throttle linkage, and choke lever.
- Try to start your generator again.
9. Valve
There are two types of valves for all generators: the intake valve and the exhaust valve. These two valves contribute to the combustion of the engine, ensuring the generator starts as expected.
But in most cases, these are the reasons why generators usually don’t start or take time to start because the valves have lost their timing or have worn out.
While it’s okay to troubleshoot your generator, in the case of valves, it will be better if you visit a professional if you are not one to help you out with it. What usually causes valve issues is if the generator is blowing white smoke.
Final Thought
These are some of the most common reasons why your Generac GP5500 won’t start and how to fix them. By following these steps, you can troubleshoot and repair your generator yourself and save time and money. However, if none of these solutions work or you encounter any other problems, you should contact a qualified service technician for further assistance.
I hope you found this blog post helpful and informative. If you have any questions or comments, please feel free to leave them below.
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