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Troubleshooting Small Engines

Troubleshooting Small Engines

By Dan Galvin / Published May 2022

troubleshooting small engines
Photo by iStockphoto.com/NoraVector

Imagine you’re out on a power washing job and your pressure washer engine won’t start. You’ve pulled the recoil start so many times that your arm feels like it’s about to fall off, or after several unsuccessful attempts the engine battery is now dead. Sound familiar? If so, this article is for you.

Murphy’s Law states that you never run out of things that can go wrong. Pressure washing engines are no exception! But, before you start tearing your engine apart because it won’t start, here are some of the most common problems with small engines.

Before we get into engine troubleshooting, I must emphasize this—MAINTENANCE! Lack of proper maintenance will cause problems and will shorten your engine’s life. At EnviroSpec, we have customers who average 5000 operating hours from their engine because they have a maintenance schedule and stick to it. Always read the engine manual before starting, operating, or servicing your engine to avoid personal injury or property damage.



With electronic fuel injection engines (EFI), many of the problems referenced below won’t be an issue. However—citing Murphy’s Law again—some will. Some of these problems sound so simple you may think it won’t be an issue for you. Believe it! These situations happen to the best of us. They say, “Nothing is as invisible as the obvious.” Often, we get so busy that the obvious hides in plain sight, so check for these common engine issues.

Problem: Your Engine Turns Over But Won’t Start.

  • Do you have fuel?
  • Is the fuel valve on?
  • Is the on/off switch on recoil start)?
  • Is the plug wire(s) attached to the plug?
  • Is the engine flooded?

The first three bullets are self-explanatory. Check and then add fuel, turn on the switch, or attach the plug as needed.

When I was working in the field and my engine wouldn’t start, I would spray some starting fluid into the air intake. If the engine kicked over, I knew it was a fuel problem.

To check and see if the engine is flooded, you need to remove the spark plug. If it smells like gas and/or looks wet, the engine is probably flooded.

One of the easiest and safest ways to fix a flooded engine is to put a new spark plug in. If you don’t have a new plug, remove the gas-soaked plug and dry it off. With the plug removed, turn the engine over to blow out any excess gas. While you have the spark plug out, you can test to see if it has a spark. The plug needs to be grounded to the engine for this to work.

Lay the plug on the engine block but not near the plug hole as the spark will ignite any fuel in the cylinder and can cause a fire. Open your trigger gun, turn the engine over, and look for the spark. DO NOT HOLD the plug when you test for the spark; the shock hurts! Full disclosure—yes, I know this from learning it the hard way!

There are other ways you can remove the gas from the plug and cylinder—resist the urge to do so. They’re not safe and you might burn yourself.

If you don’t use your pressure washer for the winter months, manufacturers recommend you put a fuel stabilizer in the fuel before you store it. I have seen the fuel gunk up in the float bowl in just a few months.

Problem: You Turn The Key, And Nothing Happens.

  • Is your battery dead?
  • Are your battery cables loose or corroded?

Most of the time the problem is caused by loose or corroded battery cables on the battery. Check all the connections and connect cables or replace as needed.

Problem: Starter Motor Spins But Does Not Engage

  • Are the battery cables on backwards?

Backward battery cables happen more often than you’d think they would. I received a call from a customer saying he just got his new engine hooked up and started, but it just spins. I told him that the battery cables were on backwards. He said, “I’ve been doing this for 20 years. I know how to hook up a battery!” I asked him, “Please check.” Then I heard him say “Dang!” and he hung up.

Problem: The Engine Runs For A Short Period of Time and Then Shuts Off.

  • Is the engine low on oil?
  • Is the spark plug broken or the wire loose?

I had a guy come to our shop with his pressure washer, saying it will only run for 30 seconds and then shut off. I looked at his pressure washer and asked him, when was the last time you checked the oil? I topped off his oil and the pressure washer ran great.

Most people don’t know this, but 20 percent of the small-engine cooling is through the oil. If your oil is old and/or dirty, you will shorten the life of the engine.

If you think the problem might be the spark plug, remove the spark plug wire to get access to the spark plug, then remove the plug. If it’s broken or worn, replace it. Doing so should resolve the problem.

That’s a maintenance lesson another customer learned when he stopped by the shop with his Kohler 14-horsepower, single-cylinder engine. He told me he ran the engine for a short period of time, and then it would shut off. I asked him if he’d checked his spark plug lately. A quick check of the plug and, well, you’ve probably guessed the outcome!

When it comes to common small-engine problem troubleshooting, once you know the truth, it’s always obvious. To quote Homer Simpson, “D’oh!” Hey, just chalk it up to the “live and learn” way of things, and while you’re at it, grab a doughnut and then PowerThrough!™ the rest of your day!

Dan Galvin is EnviroSpec’s president and CEO and has worked in the power washing industry for 20 years. If you have more questions for Dan, contact him at (800) 346-4876 or visit www.envirospec.com.