Stumpy, Since the mfg may have shanged names the week after they sold a large lot of the washers to the discount store to dodge warranty repairs, forget the AUTHORIZED repair center. There are lots of places that do presure washers. Likely you can do what is needed.
First ya gotta find the subject part, pressure relief thingy.
It is located next to and possibly part of the pump casting. When the pump tries to move water and the trigger is closed something has to give since as said before, it is hard to conpress water very much. The pressure relief is something like a spring loaded valve that holds pressure against the pump output untill the pressure goes beyond its setpoint and then the spring is compressed some more and lets some water get by it
Essentiall what is happening is the pressure relief opens up a "SHORT CIRCUIT" path for the high pressure water to get from the output side of the pump back to the input side. There are other ways to do this but this is a common one. You could just let some water spray off into the air when it wasn't allowed by the trigger to go out the wand. It wod work fine but would be a pain with all the water sprayong all the time whether you wanted it or not.
Did you run the engine by starting it with the trigger pulled and let it pump high prressure water through the wand? You need to try that. Then while the unit is seeming to pump normally you let up on the trigger for just an instant and then pull it again right away. Do this several times, each time letting up on it for just a little more time. Maybe after 20-200 repetitions the pressure shocks will break loose the bypass. IF you just let up on the trigger completely for a while with a stuck bypass the engine will stall immediately and it is conceivable you could damage something in the pump, blow a seal or gasket or ...
Sometimes there are plugs or caps with hex heads (allen sometimes) on the pump casting. Typically one of thiese is the bypass. IF you open it and find a spring and or maybe a piston (not the pump piston) you could try penetrating oil and gentle taps with a piece of wood between the part and the hammer. Something in there is most likely a bit corroded and therefore sticking. IF you don't feel mechanically quallified to discern from inspection which parts constitute the pressure relief then put penetrating oil on, in, and around everything that could conceivably move (that is in the path of water) and try to "wiggle" everything that looks like it could move, especially if it has a spring involved.
Alternatively, you could run the thing briefly with no water to get water out of it and blow it out with air if available and then pour in a lot of WD40 and penetrating oil into the water intake and with the spark plug wire removed pull the starter cord repetitively, adding more penetrating oil between pulls. You can disconnect the wand which will relieve the pump so it is easier to pull the starter. I'd continue this untill I got a significant quantity of penetrating oil coming out the wand connectiion port.
NOTE: It is always possible that somewhere there could be a seal or gasket that will not like to be in contact with WD40 and or penetrating oil for an extended period (or at all.) I have never seen this in a sprayer but it is possible. If all this fails (and I have only outlined work totaling less than an hour) then try to put it all back the way it started out and after replacing the spark plug wire o the plug, run the engine with the triger pulled and water being pumped through to clean out the chemicals. Now take the thing to a shop that "DOES" pressure washers.
Failing that, sell it, toss it and replace, or wire the trigger open and suffer to have it spray all the time it is running.
Oh, by the way, did I mention that I have only used or owned one cheap engine driven pressure washer I bought after my electric one finally died? So I am giving generic advice NOT built on decades of intense professional experience.
[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]