Question about Dewalt 4200 PSI - 4.0 GPM Belt Drive Gas Pressure Washer

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What kind of spark plug for a 4200 PSI dewalt pressure washer?

Posted by Anonymous on


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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

  • 942 Answers

SOURCE: My DeWalt Gas Pressure Washer Model DPD3100 is


Just try the following steps

  • Inspect the water supply connections
  • Inspect the drain hose
  • Inspect the water pump
  • Inspect outer tub for cracks or corrosion
  • Inspect the tub seal
  • Inspect the tub bearing
Good luck



Posted on Jul 05, 2009

  • 197 Answers

SOURCE: cannot get it to uptake the bleach for spraying

On most pressure washers you wont be able to draw soap/bleach into pump unless you are spraying on low pressure.There is a valve on the inside of inlet hose fitting that closes when high back pressure is sensed.Would it draw bleach into hose when wand tip is removed?

Posted on Nov 21, 2009

  • 45 Answers

SOURCE: Hi, I have a Dewalt pressure

There are two common issues that will cause what you are describing. What you need to do is run the machine until it dies as you are describing. Then pull the spark plug and check for spark. If you do not have spark you have a failing stater. It is very common for this problem to only show itself after the machine warms up. If you find that you do still have spark try removing the gas cap and restarting. It is also common for a vacuum lock to occur due to the seal on the gas tank cap. In most cases one of these will be your issue. If not feel free to contact me at 800.247.8103 and I will help you to troubleshoot the issue further.

Aron Kerr
Landa Northwest

Posted on Mar 10, 2011

  • 146 Answers

SOURCE: Hi, My Dewalt 3100 pressure

The Dewalt 3100 came with 2 different pumps. The Blue Cat pump and the oil free pump that was made by DeWalt.
You may just have a bad Thermal relief Valve on the unit.

You can find the parts diagram at

Posted on Oct 01, 2011

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1 Answer

Working ran out of gas added gas and won't start??

Remove spark plug and clean with dry cloth and then put a teaspoon of gas in the hole where spark plug was installed. Next reinstall spark plug and try starting. It should start.

May 10, 2015 | Dewalt 3800 PSI Pressure Washer

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Why does my power washer back fire

Try to clean the spark plug and make sure it is gaped properly
Best of luck!

Sep 25, 2014 | Dewalt 3800 PSI Pressure Washer

1 Answer

Spark plug size for pressure washer

Just pull out the suspect plug and replace with same.

Sep 06, 2014 | Dewalt Pressure Washer. 4200 PSI 4.0 GPM...

1 Answer

How do I release pressure from the hose on a pressure washer

would it be possible to unscrew the quick connect fitting SLOWLY until water starts to drip out of threads thus allowing the pressure to drop down slowly to the point of being able to release the hose coupler?

Jul 28, 2014 | Dewalt Pressure Washer. 4200 PSI 4.0 GPM...

1 Answer

What oil weight is used in the pressure washer pressure unit

Non-detergent 20-30-weight goes into pump port, and is filled about half way.
Ordinary motor oil 10-W30 or 40 goes into engine port.

Nov 11, 2012 | Dewalt Gas Pressure Washer: 4200 psi 4.0...

1 Answer

What oil to use

Your manual will say to use General pump oil GP100..or whatever DeWalt's number for that may be. See for their proper part number. From the pictures of that model I see on line, that is a General Pump and they have recommended Non-detergent 30w standard motor oil in the past. We like to use a non-foaming full synthetic 20-50w racing oil on these high RPM pumps.

Oct 20, 2012 | Dewalt DXPW4240 4200 PSI Direct Drive...

2 Answers

What PSI will the simpson Model WS5040H maintain while in use? I have had difficulty getting anywhere close to the rated PSI on a DeWalt 4200 PSI unit. Idle the pressure stays at about 4200 but as soon...

Engine is difficult to start when cold
  1. Check the battery condition, battery state of charge and starter motor current draw. Replace the battery if marginal and the starter motor if the current draw is beyond specification.
  2. Check the battery cable condition. Clean the battery terminals and replace corroded or damaged cables.
  3. Check the fuel system for proper operation. A fuel pump with insufficient fuel pressure or clogged injectors should be replaced.
  4. Check the engine's tune-up status. Note the tune-up specifications and check for items such as severely worn spark plugs; adjust or replace as needed. On vehicles with manually adjusted valve clearances, check for tight valves and adjust to specification.
  5. Check for a failed coolant temperature sensor, and replace if out of specification.
  6. heck the operation of the engine management systems for fuel and ignition; repair or replace failed components as necessary.
Engine is difficult to start when hot
  1. Check the air filter and air intake system. Replace the air filter if it is dirty or contaminated. Check the fresh air intake system for restrictions or blockage.
  2. Check for loose or deteriorated engine grounds and clean, tighten or replace as needed.
  3. Check for needed maintenance. Inspect tune-up and service related items such as spark plugs and engine oil condition, and check the operation of the engine fuel and ignition management system.

May 09, 2011 | Simpson WS5040H Water Shotgun 5000 Psi...

1 Answer

Dewalt Pressure washer keeps shutting off for no reason. plenty of gas and oil, water running to it. starts fine and as soon as I start spraying it shuts down.

Had a similar issue with my dewalt 4200 pw. Unit starting shutting off after spraying for about 5 min. Then difficult to restart, but would start again eventually only to shut down a few min later. Had new engine oil, new pump oil, good gas. I changed the spark plug and unit runs great again!

Aug 08, 2010 | Dewalt 3800 PSI Pressure Washer

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