i have a craftsman power washer with a b&S 4.5 quantum motor . heres my problem I let the engine warm up then I throttle it up to wash . After that it doesnt havr any pressure like the pump isnt kicking in but cut throttle back to half and it works good . what do you think my problem is? qany help would be appreciated.

Please dont tell me I have stumped everyone here.??? BUt if it does it does really any help would beappreciated.

it could be the valves are sticking or the pistons are worn and when at a fast speed the water is just blowing past them