Hey guys, Thanks in advance for your help. I have a 3100 PSI Ryobi w/Honda engine. I just replaced the hose and wand, and checked the unloader valve and I am still losing pressure.

Walk with me and I will explain what's going on:

I hook the water hose and high pressure hose up to the machine. I hook the high pressure hose up to the wand. I turn on the water to wide open. I fire up the Honda engine with trigger depressed and a 40 degree tip in the wand. Once motor is running I release the trigger. I hear the motor rev up & idle back, typically indicating the pressure washer is ready for use. I pull the trigger and great pressure. Within about 5-10 seconds of holding the trigger the water pressure is barely sputtering out. When I release the trigger, the motors revs up high and idles back (again indicating the pressure washer is ready for use). Repeat as many times as you feel like it... This happens no matter which tip I put in 0, 10, 15, 25, and 40.

Makes sense?

Again, I have checked the unloader valve and it is not stuck. I have replaced high pressure hose & high pressure wand.

Please help

Yes it is.

There is no pressure problem with hose or water supply pressure. I figured it was a pump problem. The closest reputable place in my town that will service pressure washers costs $70/hr labor rate. So I bought a new pump from partswarehouse.com.

Now a new problem. I've unbolted the pump from the engine (vertical shaft) but the pump won't come off. Is there a trick to it?