10 Reasons Your Pressure Washer Won’t Start (With Fixes)

With summer comes warmer weather. And with warmer weather comes the need to clean. As proven with the latest and greatest in technology, the best way to really get the wintertime dirt off of your property is by using a pressure washer.

Pressure washers are a great tool for anyone who likes to clean surfaces quickly and cheaply by themselves. They can especially be helpful with projects such as cleaning your patio, washing windows, or soaping up your car. Sometimes though, you may find that your pressure washer is a little difficult to get started, or won’t start at all.

Keep scrolling for the top ten reasons your pressure washer won’t start or stay on, whether it’s electric or gas, and some suggestions and step-by-step guides on how to fix it.

Why Your Electric Pressure Washer Won’t Start

Reason One: The Spark Plug

Be sure to check your spark plug for any signs of damage or even slight wear. It can cause a problem if the porcelain insulator is cracked, there is heavy carbon buildup at the electrode, or the electrode is burned or somehow damaged.

To test out if it really is no longer usable, you can use a spark plug tester to determine if any electrical current is reaching it. Seeing as the current is used to detonate the air and fuel mixture inside the cylinder to create the power it needs to run, it’s a pretty necessary part of your engine.

To fix this, simply just replace it. It is recommended anyways that you replace your pressure washer spark plug after every one hundred hours of use, or every season, whichever comes first. This will help you keep an efficient fuel economy and ensure your pressure washer starts every time.

For more instructions on how to change out your spark plug on your pressure washer, be sure to watch the video below:

Reason Two: The Carburetor

If you’re using a gas-powered pressure washer, your problem may be a little more complicated. This is because gas and the mechanics needed to process it can easily become gunked up.

Leaving old fuel in your pressure washer over the winter season is a common mistake people make when first using a pressure washer as it can cause a clogged carburetor.

Seeing as over time gas can evaporate, it will leave behind a thick, sticky substance made of different ingredients that can clog things up, keeping the engine from starting. If you find this to be the case, all you need to do is clean it out.

Use a carburetor cleaner to get all of that gunk out. If this doesn’t seem to work, you can also try rebuilding or replacing the entire carburetor.

For an in-depth cleaning tutorial, check out the video below:

Reason Three: Ignition Coil

Your ignition coil sends voltage to your spark plug while the engine is started up and running. If it becomes defective, it can be a major reason why your engine won’t start.

To fix this, all you need to do is replace the ignition coil. But before doing that, you need to ensure that your spark plug is working, as that is more likely the problem. If your spark plug is in fact working, you can use an ignition coil tester to troubleshoot the problem even further.

Replacing your ignition coil is pretty simple, can be done in just a few hours, and with household tools.

For more detailed instruction on how to replace your ignition coil, be sure to watch the video below:

Reason Four: The Flywheel Key

The flywheel key is a tiny piece of metal that fits into the crankshaft and engages with the flywheel. The flywheel is designed to serve a few different, very important uses.

One use is keeping the engine cool by distributing air around the engine block. Another is maintaining the right engine speed by blowing air across the air vane on a pneumatic governor. The magnets mounted on the outside of the flywheel are also required for the engine’s ignition, so they can’t be damaged.

If the engine won’t start or it stops suddenly after you’ve hit a hard object with your pressure washer, your flywheel key may have broken in half to prevent any damage to the engine. If it breaks, simply just replace it.

To fix a problem with the flywheel key simply just:

  1. Disconnect the spark plug lead and take it away from the spark plug.
  2. Remove the bolts holding the shroud in place, and then remove the shroud.
  3. If your engine has a flywheel brake, remove the cover.
  4. Disconnect the outer end of the brake spring.
  5. If your engine has a flywheel clutch, remove it. Be sure to hold the flywheel with a flywheel holder or strap wrench.
  6. Be sure the flywheel nut is threaded on the crankshaft. Install a flywheel puller so it engages the holes on the flywheel’s hub.
  7. With the flywheel nut threaded onto the crankshaft, install a flywheel puller so its bolts engage the holes adjacent to the flywheel’s hub. If the holes are not threaded, use a self-tapping flywheel puller or tap the holes using a 1/4 X 20 tap.
  8. Rotate the flywheel puller nuts evenly until the flywheel pops free. Then, remove the flywheel and key and replace them with new ones.

Reason Five: No Gas or Bad Gas

If you need a bit more power and you’ve been using a gas-powered pressure washer, you need to keep tabs on how full your tank is and how fresh your gas is. A common mistake people make is not realizing that they have simply just run out of gas in their tank or they are using old gas.

Regular gasoline also only lasts about six months, so it’s best to use it up completely before it starts to do damage to your carburetor. It’s also pretty easy to add a fuel stabilizer to the tank after filling it up. This can help it to last for months longer than it would regularly.

For optimal performance, use your gas up or switch your gas every one to three months.

Reason Six: Change The Oil

Changing the oil is a necessary maintenance routine for any engine, big or small. Even in electric pressure washers, you will need oil for the pump to work, so you need to change it out two to four times a year.

It’s best to replace the oil in your pressure washer every 200-250 work hours, or every three to six months if you use it frequently. A great way to remember to do this is to schedule to do it right alongside changing your car’s oil if you do it manually.

Reason Seven: The Electric Outlet

In this age of electrically powered tools, it can be easy to forget that sometimes outlets have a tendency to stop working.

Test the outlet you are using by plugging something else in and making sure a connection is made. If nothing works using that outlet, simply just use a different one. But if that doesn’t seem to be the problem, be sure to look over the power cord to your pressure washer and make sure it isn’t broken or frayed in any areas.

Something you can easily look over is the power requirements of the pressure washer. If the output voltage of the outlet is too low for what is required for the pressure washer it won’t work.

Reason Eight: Replacing The Air Filter

The air filter in your pressure washer helps to keep dirt, debris, and other nasty stuff out of the inner parts of your pressure washers engine, helping it to last as long as possible.

If you find your pressure washer, especially gas-powered ones, are experiencing a lack of power, then an easy fix may be to clean or replace your filter.

Clean your air filter by soaking it with clean engine oil about every three months or fifty hours (or ten hours if you work under extremely dusty conditions.) A dry or little-soaked air filter will only be able to trap larger particles, which doesn’t do your engine any good in the long run.

Here are some general steps to take to clean your air filter:

  1. Always disconnect the spark plug.
  2. Remove the air filter cover.
  3. Remove the wingnut on the top of the air filter assembly.
  4. Pull out the entire air filter.
  5. If you are replacing it, put in the new air filter and put the wingnut and cover back on.
  6. If you are cleaning the old filter and reusing it, place it in a tub of soapy water to wash out all of the debris.
  7. Place it in a tub of clean water to then wash out all of the soap residues.
  8. Dry it out with a clean napkin and let it dry out in the sun for about thirty minutes. Make sure no damage has been done after this process.
  9. Add some oil to the sponge to make sure it’s well saturated and put it in a zip lock bag. Massage it while it is in the bag to allow the oil to cover it entirely while saving your hands from the oil.
  10. Get any excess oil out in a dry napkin.
  11. Reinstall the filter in the housing and replace the cover.

Reason Nine: Repair Or Replace The Pressure Washer Recoil Starter

If your pull rope doesn’t pull or retract properly, then it’s likely your engine won’t spin when you pull the starter rope. This is an easy fix, as you will just need to replace the recoil starter to make starting your engine possible again.

Here’s a few steps that will make replacing your recoil starter easy:

  1. Remove the nuts that hold the starter assembly to the engine and lift it up.
  2. Pull out the rope that is left in the starter assembly, being careful not to pull it too hard, until you can get to where the rope is attached.
  3. Secure the pulley with a small screwdriver to keep it from automatically winding back in.
  4. Untie the end of the rope or cut it off at the end if you are going to be replacing it.
  5. To replace the rope realign the hole in the pulley with the hole in the housing, keeping in mind the inner part of the mechanism needs to be turned to where it has tension on the spring.
  6. Resecure the pulley with a screwdriver to keep it in place.
  7. Thread the rope through, which may take a few tries. Once inside, tie a knot at the end of the rope and superglue it to keep it from ever coming undone.
  8. Let the rope recoil back in, stopping it when only a few feet are left hanging out. Tie an easily undoable knot in the middle of the exterior part of the rope to make sure it never goes inside of the housing, allowing you access to those few feet.
  9. Put the housing back on top of the starter assembly and secure it with the nuts you took off.
  10. Take the starter grip and remove whatever rope is left on it. Thread the end of the rope you just installed into the washer, and tie a knot, putting some superglue in it if you want.
  11. Thread the rope back on the eyelet of the handle for easy access.

Reason Ten: Low Or No Water Pressure

Good, working water pressure is key to getting things clean with your water pressure. But it seems to be a common problem to find yourself with little or no water pressure. Thankfully they can be solved by some pretty simple solution.

If there’s low pressure, the problem, generally, isn’t with the machine, but rather your water source. Unkink your hose, double-check whether your tap is opened all the way, and be sure to use a garden hose that is large enough for your needs in terms of diameter.

If those requirements are all met, be sure to check your hose for leaks. A lot of people will use a hose full of holes and not realize it for a while. If there’s still little to no pressure, be sure to check that there isn’t any debris or mineral build-ups in the inlet water filter.

When there is no water pressure, you could be dealing with a damaged unloader valve or damaged pump inlet values. To solve that problem, readjust the unloader screw and change any damaged seals/springs.

If your pressure washer has high pressure that drops down suddenly, you may have different problems than the ones listed above. To restore your water pressure, disassemble your pump and replace/clean the inlet manifold.

For more information on how to fix these types of problems, check out the helpful video below:

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