DeWalt Gas pressure washer Parts — Browse All Models

How to fix your DeWalt gas pressure washer when the engine loses power

The engine requires an adequate supply of clean air to run properly, so replace the air filter if it's dirty. The engine also needs clean, fresh gasoline, so replace the fuel in the gas tank if the fuel is older than 3 months. If the carburetor is gummed up, the engine loses power, so check the carburetor and rebuild it if necessary. Replace the carburetor if it's too dirty to clean.

If the engine starts and run fine for several minutes but then loses power, the unloader valve may have failed. A failed unloader valve won't recirculate water back to the pump inlet, so pump outlet pressure builds up, making it harder for the engine to run the pump. The engine bogs down when it struggles to run the pump.

Try this test to see if a bad unloader is causing the engine to lose power. Stop the engine and remove the nozzle from the tip of the wand. Start the engine and hold the wand trigger down so water flows freely out of the wand. If the engine continues to run smoothly instead of bogging down after several minutes, then you'll likely need to replace the unloader valve.

How to replace a DeWalt gas pressure washer unloader valve

• Pull the spark plug wire off the spark plug on the pressure washer engine.
• Use an open-end wrench to turn the unloader valve counter-clockwise to remove.
• Install the O-ring from the kit on the new unloader valve. Lubricate the O-ring on the new unloader valve with silicone lubricant. Thread the new unloader valve into the pump and tighten.
• Reconnect the spark plug wire to the spark plug on the engine.