If you get that smaller engine, you’re gonna have to get a smaller pump.
One with either less psi, less gpm, or both.
I’d honestly get rid of that small machine and get you something that’ll make you more money.
Maybe get a new 11hp engine for like 300 bucks and keep that one either as a backup, or to have a helper do jobs with you.
You can get 4gpm 4000 psi belt drive or gear drive machines for $1500 - $2200, depending where you shop
