Like this?
Amazon.com: Comet PTO-Driven Cold Water Pressure Washer - 3000 PSI, 5.5 GPM, Model# PTO SW 5540: Home Improvement
Just looking at comet's catalog, they seem to be rated at twice to generally three times the RPM of a PTO. As the rated RPM goes down, the GPM requirement goes up.
Dan I like
this one a LOT more!
I have a 13HP Honda powered hydrojetter w/ a 4SF CAT PUMP that
needs a rebuild or replacing. Yesterday I priced it at over $1K or about
$600 to rebuild. I went huntin' for like pumps and found General Pump Co.
I called and spoke to "Ron" at GP and he spec'd me out a like pump, w/
pulsation and unloader. I went pricing and found it all, all new parts for
about $575.00 so I will pull that trigger this morning. I found Ron to be
very knowledgeable / helpful. 888-474-5487 x125 . They will not sell
to you but you will get the info you need. I do not know if they sell a
PTO pump or not...but a plethora of info he is.
I bet if you pull off your Hose bib, and replace it w/ a full port ball valve
w/ a 3/4"MIP x MaleHose adaptor you can bump up your GPM's
significantly. I call that set-up a Little FireFighter and install it much to
many clients delight when I do water services, BEFORE the pressure reg
if there is one...