20 Most Recent Dewalt Pressure Washer - DXPW3025 Questions & Answers

Look at the size of your spray nozzle, it may be too small causing excessive back pressure and thus excessive strain on your engine. Your nozzle should be a 3.0. If you are using the 25 degree nozzle for example, it should say 2503 on the side of the nozzle.

there should be a metal plate with numbers. or numbers stamped on the engine cover. if you take these numbers to a parts store they can cross reference the and tell you what you need to know. that is how i find out. good luck

get larger nozzles, if you are using size 4 nozzles now ( looks right for 3 gpm at 2500 psi) then you would use size 4.5 for 2000 psi, size 5 for 1600 psi etc Chart here https://www.stens.com/assets/media/pdf/2012_Nozzle_Size_Reference_Guide.pdf

Your unloader bypass system has failed. Several pumps were used on this model, see link for parts breakdowns.

The seal inside the unloader has gone. It is normally an O ring and should be able to be replaced or get a new unloader.

Try disconnecting the oil level switch.

The after fire solenoid helps prevent backfire when the engine is turned off. You can operate the genset without the solenoid and likely it will shut off without issue.

You can easily test by removing the solenoid plunger or the tip of the plunger and reinstall the solenoid.

page 15 DeWalt DPD3800 Instruction Manual Nozzle Cleaning

There should be a mark on the dipstick min and max. Keep within the 2 marks.

spark plug wire? do you mean coil? if you have no spark. i would check the plug first. then the coil assuming the on of switch is good. unplug the coil kill wire and try it. if it starts then you have a switch or wiring problem. if it don't start it is likely the coil is bad.