38 donzi ZR mph
 

Just got our new boat. A 2007 38zr with 525's (staggered)

It seems that most with this boat are hitting high 80's on fresh water. We are only getting 79 mph with 32 pitch 5 blade props.

Anyone have any ideas?

At 3,000 rpm 42mph
At 3,500 rpm 53mph
At 4,000 rpm 62mph

Wot and over trimming it (about 6) I can get it to 4,900 rpm

Thanks for the help

Welcome aboard..... If your motors check in ok and all...seems like you are going to be dialing in a bit with props. You'll get the answer you need as there are several here with the 38ZR.

Start messing with props. Find a set of 32-33 4 blades and some 30 5 blades. How much fuel is in board and weather tempature are big things to consider. As well as how many people and beer of course. Lol

Just a quick observation... 525's with 5 blade 32's...too much prop. 38 T/S Top Gun will run a average 86-87 with 4 blade 32's with the same motor. I know the Gun is heavier but I think the comparison is good enough.

Chris

It is not a comp and the weather was pretty good, about 75

It was just my wife and I and we had about 60 gallons of fuel. So not a lot maybe a little over 1/4 tank or so

The motors have about 100 hrs on them and they were leaked down before we bought it. So I was told.

Also. Inside the props are very carboned up and when idling around it smells very rich? I have never had 525's before so maybe that's normal?

The other factor is prop rotation, you spinning in or out? In is faster

Something doesn't sound right. The couple I've been in with your set up were solid mid 80s boats regardless of fuel. I don't know how far you ran it but it might take a little distance to get that last few mph.
Let's see some pics.

Spinning in. Ran it wot for about 2 miles.

I'm with you something doesn't seem right. Frustrating

Somebody took the props off a different boat when it was sold. 525's dont have captains call how can there be carbon in the props? Maybe the props are hideously wrong for that hull?

It does have silent choice. With the silent choice on does it not go out the out drives through the prop? I don t know