The maximum utility category weight for the -9's is 1600lbs, with the maximum gross weight recommended being 1750lbs.
It is irrespective of engine size, though with a smaller - lighter - engine you have a higher payload before hitting either of those limits, while still achieving 900FPM climb at max gross.
In some jurisdictions the MTOW may be limited by legislation, ie mine is currently limited to 1320Lbs MTOW until I can get it re-registered with CAsA.