Karcher power washer woes

[DIYer]

I obtained a real nice Karcher power washer for FREE this past weekend with a 13hp Honda motor. It runs perfect but when you hook a water line hose to the pump and turn the water on it basically stalls the engine. When you shut the engine off you can barely pull it to start it again. Could the pump be plugged or seized? I figured if the engine ran the pump isn't seized cuz it is direct drive, unless there is a valve stuck that is restricting water flow? FYI, the washer has a new gun and gun hose. Shouldn't water run freely out of the gun when the trigger is pulled even when the engine isn't running?

[AZScooter]

It sounds like you have a bad unloader. They can stick closed on rare occasion and cause the problems that you are describing. The unloader is that brass thing with a knob or bolt on top that is attached to the top part or pressure side of the pump head. SOmetimes they have a hose between it and the pump and another between it and the inlet side of the pump.

If you take it off, and turn on the pump and motor with water hooked up, it should flow water really freely, and very possibly, even when the motor is off. Another simple thing that you can check is to remove the nozzole and see if it is plugged. I have had it happen where the nozzle was plugged and the machine would not operate. (I felt stupid afterwards, too) These are a couple of quickl and easy checks for you.