Honda Engine and Replacement Pump

I have a Honda 270 sitting around. Looking to put a pump on it to have a backup machine. Can I run a 4/4 off this size engine or is that too much? By no means an engine expert so looking for advice. Thanks!

GX390 (13hp) is standard for a 4/4. You’re looking at 3/3500 or 3.5/3000 probably for your GX270

Ok thanks!

GPM x PSI ÷ 1100 = required HP

Never knew that. Thanks!

That formula is interesting. I found out the pump on my gx630 is not maxing out the HP rating by 4hp. I’m pretty encouraged by that if I ever want to upgrade.