What 8gpm GP can I pair with a Honda 670?

Have a 5.5 gpm in there and I want to upgrade. Engine can handle it just need to figure out the rpm correct?

Call dultmeier. The Udors are the same as GP’s basically from a cost standpoint. But any 8 gpm/3000 psi pump should work. Maybe even 3500. Those hondas run at 21 HP if I recall.

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22 and was told 24 if I use premium fuel.

looked up the specs for 660. 21.5 so 22 is about right. But with other variables don’t count on fuel giving you up to 24. Buy an 8/3500 and you’ll probably get 3250 with all other variables accounted for. The 8/3500 will work for that engine.


Find out what your current pump runs at. Just look up the pump model you currently have, and you can about figure the rpms by how much gpm you’re actually running vs what it’s rated for rpms/gpm. I have two GX670’s that were pulleyed down from 5.5 to about 4.5 by Shark. They run about 1600 rpms at the pump. If you’re putting out 5.5 doing a bucket test, good chance you’re running about 1750 rpms, though a few pumps run 5.5 at 1450 rpms. I swapped to a TSF2021 on one, and am about to get another one for the other machine. Technically, it’s rated 8.8 gpm at 1750 rpms by GP, though everyone else sells them as 8.5 or 8 gpm. Mine runs about 8 gpm. I just swapped mine right in, no new pulleys. You will possibly need a new pulley bushing for the pump pulley, but most parts houses can cross reference the old one’s part number that’s stamped on it, and get you the right sized one.

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Yeah it’s the 5.5 3500 gp pump