Tried the chit chat with no luck but tried some new ideas.

I've got a recently acquired Excell XR2600-1 w/ a Honda engine. It ran fine last weekend while pressure washing the sidewalk. Now the unit will only "start" for a second or two then shut off. If you bump it with starting fluid it will run fine, regular RPMs and build pressure and work without issue. If you stop the stream of starting fluid it shuts off. It will idle, without water pressure with the choke full on but as soon as the water is turned on and load applied the unit stalls.

UPDATE

I took everything apart this weekend, the carb is non adjustable. I checked for any signs of problem and nothing stuck out. Took the bottom bowl off the carb, cleaned it up, drained the carb, didn't see anything in the fuel.

I then checked the fuel lines, all flowed well, no clogs. The mechanical pump seems to work fine but can't really tell. The gaskets were in good shape and sealed up no problem.

Re-assembled the entire unit, fired it up, again, unit would not run w/ anything other then 100% choke. With the water on it would stall out without the wand being pulled but would run with the wand pulled to the spray position.

Ran it for about 15 or so minutes with the choke on, it put out about 60% pressure. When I would let off the wand the engine would stall out. I toyed around a bit more and all of the sudden when I let off the wand the engine would bog way down then ramp back up once the pump when to bypass. The engine would still stall out when the choke was pushed in (off). I could use the pressure washer no problem with the choke on.

Is it possible I'm completely wrong and the pump maybe bad?

If its anything like the fourwheelers and stuff i've had, I'f it wont run with out the choke on you've got an issue in the pilot side of the carb, I would imagine that passage is very small. Did you just open and inspect or take a shot at cleaning out the passages?

If its anything like the fourwheelers and stuff i've had, I'f it wont run with out the choke on you've got an issue in the pilot side of the carb, I would imagine that passage is very small. Did you just open and inspect or take a shot at cleaning out the passages?

I looked but as you said it's small and it looks sealed (no adjustment at all can be made). I can take it apart and spray some carb cleaner in there to see what, if anything breaks free, I didn't have any carb cleaner at the house so I'll pick some up.

I know even some of the smaller stuff has a pilot jet, and on something that small the orifice would be TINY, so all it takes is a little piece of crud to ruin your day