‘03 Donzi ZX Performance??
 

A buddy of mine just purchased a 2003 38 ZX w/ 525’s. He and I ran it today and boat seemed extremely slow. Couldn’t get more than 60 mph at around 4,500 rpm. Motors have been scanned and no codes and all cylinders firing. Not sure on props as it was already in the water. Anyone out there with a similar boat and can give me some performance numbers? Much appreciated

Was the boat test run in water before the purchase? If so how fast did it run?

I would think 80+mph it should run.

RPM should be near the limiters at 5,400 but it sounds like something more serious than being over propped.

79-80mph trimmed out an half tank best I ever saw in a 38/525. Thats A LOT of boat to be pushing. (12k Dry)

What he said. ^^^

I don't believe after 17 years, the boat has the wrong props. Revs are very low, I'd be checking engines.
Stupid question maybe, it's not antifouled and dirty is it?

Nice looking boats, hope you get it sorted quickly. :)

RR

As said already, top RPM should be 5400 and max speed is 78-80ish