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View Full Version : Possible prop changes from 28ZX ???



stationinc
03-19-2013, 08:28 AM
Have 2001 28ZX w/ twin 350s
Both run good
Have 3 Blade props @ this time & thinking about changing to (5 blade hydromotive P-5X 28" props)
My top speed @ this time is approx 60mph

Can anyone give me some insight regarding these props
How much do you think it will help w/ plane out & top speed ???

Can e-mail direct to:
stationinc@aol.com

VetteLT193
03-19-2013, 08:53 AM
I have a prop thread going in the donzi section of Offshoreonly. Probably worth reading through.

Something is wrong with your speeds.... at what RPM do you see 60? What 3 blade props do you have now specifically?

My assumptions (correct me if I am wrong please)

closed deck version, not the open bow
1.5 ratio drives
No bottom paint
Things are running properly overall


Assuming that is what you have your best top speed will be had with 23 inch Mirage Plus props. That should get you to 70 MPH plus or minus based on conditions/load/etc.

If for some reason you have a different setup post it up and we can help more.

As far as the 5 blade... they will get you a great cruise but slow you down for top end. Really, the Bravo 1 4 blade is a great cruising prop on this hull (that's what I use 95% of the time). They pull 5-ish MPH off of the top end though resulting in 65-ish for me (6.2, open bow, 1.65 drives so kind of a different boat)

With the assumption list above you'll never turn a 28" anything. If you went to a 5 blade you would be looking a 21 inch and no more than 23 inch. I'd think a 24 Bravo 1 might be a good fit as an alternate, they are also all over for sale and much cheaper.

Conquistador_del_mar
03-19-2013, 12:31 PM
+1 on what Vette wrote. Bill

MOP
03-19-2013, 02:51 PM
+2 on the above!

Once you are sure your power is up to snuff get yourself to one of the Donzi gatherings, all boats react differently with props. You will be ahead of the game trying before buying. Many setups are a slower with 4 and 5 blade props, my setup ended up being faster with a 4 blade go figure.

Phil

stationinc
03-20-2013, 06:11 AM
Thanks for all of th response letters:

stationinc
03-20-2013, 06:29 AM
Thanks for the responses:

The boat is a ZX closed bow
1.5 drives
Not painted, fiberglass & like new
Thisngs seem to be running properly
60mph @ approx 4000 rpms (depending on the condition)
I have 23 props on the boat now

I WILL SAY >>>>> this boat burns gas like no other boat or vehicle I have ever owned !!!!!!!!!!!!
Now I am wandering if it is tuned properly ???????
Thoughts ??????

stationinc@aol.com

VetteLT193
03-20-2013, 08:39 AM
Your RPMs are way off. What kind of 23" props do you have, Mirage Plus? I'll assume so for now because that's what the factory put on the boat. I'll take another guess that this isn't GPS speed?

My gut says your engines are throwing codes and the Merc computers are limiting the RPM in guardian mode. You are probably running an actual speed of 55-ish. Your engines should turn to 4800-5000 RPM. That's why your speed is lacking.

Run a scan on the computers to see what is going on

Ghost
03-20-2013, 11:17 AM
Quick supplementary question: what are the motors, exactly? (I saw they were 350 cu in, but what model/HP? Sorry if it's there and I missed it.)

joseph m. hahnl
03-22-2013, 09:32 AM
Does the trim work? You should be able to get the prop to slip with the trim. If it won't rev over 4000 RPM period . You need a scan tool not a prop ;)