Official Porter Cable gas pressure washer parts

How to fix your Porter Cable 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.

Troubleshooting your Porter Cable gas pressure washer when it produces weak spray

An insufficient water supply can cause low pressure at the nozzle. Check the water pressure at the source and the flow connected to the inlet of the pressure washer. Check the inlet screen for a clog that could be blocking inlet water flow.

Check whether a low-pressure spray tip is installed on the wand; if so, install a different nozzle. A problem with the wand or pressure hose can also cause low nozzle pressure. Clean or replace the wand if necessary. Replace the pressure hose if it's clogged.

A pump failure can cause low nozzle pressure. Replace the pump check valves or replace the entire pump if it doesn't build up adequate spray pressure. A stuck unloader valve can also cause low pressure at the nozzle. Replace the unloader valve if it sticks open and constantly recirculates water back to the pump inlet.