View Full Version : Cavitation problems

08-14-2012, 08:40 AM
Hi, I am new to the wonderful world of Donzi and am struggling to get my ZX 28 up on the plane and wondered if I was missing a trick. She's got 2 x 260 HP Mercruisers but has to be eased gently on the plane then she's off to 60mph without a problem. Any clues?

08-14-2012, 10:22 AM
Most of the step bottom boats do this. My understanding is that the hulls will suck air through the steps if you try to accelerate hard from a standstill. All the ZX's I've been in had to be walked up mildly then you could get on it. Some say you need to have the tabs down to get up on plane. It helps but I don't think it's necessary.

08-24-2012, 09:48 AM
This is a propeller problem.
You don't say what kind of props you have.
If your props are ventilated, (holes behind the blades) and you have thru-prop exhaust, put caps in them.
If you have 3 blade props, think about going to 4 blade.

08-24-2012, 10:12 AM
There's a whole thread about this (maybe more than one). Did some searching and found this one:


08-25-2012, 11:02 AM
1. go with less pitch props
2. more dia with less pitch
3. write down ALL finding getting on plane rpm etc, start with the wheels you have now
4. then tell us. problem probably will go away

08-25-2012, 02:19 PM
I had great success with the Revoution 4 prop I ended up using on my 25' Martini before selling the boat. They really grab and run better than the other ones I tried including a Bravo, Mirage, and cleaver. I know all boats are different, but it might be worth trying a set. Bill