OK , first time here , so thanks for any input I can get on this issue. Im working on my dads 2500psi craftsman pressure washer and can't seem to find the problem. When I turn on the water to the pw I get a small stream out of the nozzle, which I believe in normal. But when I start the engine the water flow stops and the engine boggs down and the pump gets hot. So I turn off the engine ( water still on) and squeeze the trigger and release pressure a small stream of water flows again, but stops once the engine is running. I have disconnected the hose from the pw and the same thing happens coming from the outlet of the pump. Also I have taken the inlet/outlet part that bolts to the pump ( sorry don't know the name of it) and ran the engine with just the pump bolted to the engine and all of the plungers ( 3 of them) seem to work just fine. Can anyone tell me why when the engine starts no water will come out and the pump gets hot? Thanks for any input

Hi,
Well, you did tell me that it is a piston pump, rather than an axial or radial. It got hot because water was not reaching the plungers, as you call them, to cool them. Could be the unloading valve.
Got that 9 digit model number. The first three digits tell who made it for Sears.
Peace,
Clarke