Got that question from one of my techs recently. Sent him to a PSQ 4000 that stopped putting out soap. The delivery pump and motor had gone belly up. Even from Wash World replacement was around $800 with freight. The original motor is 1.5 hp. So I gave him a .5 hp motor and small Procon to replace it for less than half. I can only imagine what PDQ would want for it, as they won't sell or talk to me. Well the little guy works great. I would bet that even a Flojet would do. So that's when the tech asks why PDQ put the bigger one on to start with. Good question. If you have one of these machines, remember this when yours croaks.