Donzi F-23's whatcha' running?

[RickyR]

I'm trying to get my engine dialed in, and was looking for anyone who has a Merc 225-250 hp on their center console.
I would like info on props, RPM's and speed data. Weight and fuel levels would also help. Any info is greatly appreciated.
I know I am close, but any little bit of advise would help both Fish ( :dolphin: ), and me.
Thanks, Ricky...

[Fish boy]

Hey Ricky, I am pretty happy with the 19 turbo so far. I am still on breaking oil on the 250efi (and oil left over from my carbed motor still in the tank, so the motor is slightly more slugish) and just creap up on and tap the limiter. Probably a 20 or a little more diameter would be perfect. half tank of fuel.

I am also running 6" of setback, which really gives the boat a great natural attitude without needing as much trim or forced bow lift form the prop.

RIght now hitting 50mph on the limiter on a break in motor, but I am getting a ton of slip due to my motor being slightly too low and the cavitation plate disrupting the water going to the prop (also causing some drag).

I will update as soon as I work out the height problem, but I am expecting mid 50's, maybe a little better once everything gets dialed in.

fish

[RickyR]

Fish,

I raised my engine to the last set of holes, and ran the 19 Sunday. I got to 53 mph, but only 5150 rpm's. I imagine if I had a little less diameter ( 15 1/4 now), I may be able to get a few more r's, but loose my bow lift???
This afternoon, I got a call back from the local prop shop, who suggested trying my 21 Stiletto again, but put a little cup in it?????
This weekend is out, I'm taking my jeep to Tellico (Murphy, NC) for a little rock crawling, so that puts me another weekend away from getting my boat ready for the poker run in Jax...
Hopefully some other folks will chime in with their specs...
Thanks again, Ricky...

[Fish boy]

ricky, I do not think you will lose much bow lift with less diameter. I am running 14 1/2 (maybe 3/4, I will check) but it is a lot less. 15 1/4 is a lot of prop, is that for a mercruier or outboard?

Before you spend a bunch of money to get your stiletto reworked, I can send you my prop to try. At least it will give you a baseline to see where you need to go. Like I said in my email, you need less diameter and to be consistent when testing them chaning pitchkeeping diameter, changing diameter keeping pitch- only change one thing at a time.

Let me know if you want to try mine out, I am using it this wekend at dora, but I can send it out after that as long as you get it back to me pretty quickly (king fish are getting ready to run down here WooHoo! Mine is not perfect, but I think you will be surprised at the grab, lift, acceleration...etc. and you will get to try a different prop to see how it works on your setup.

fish

PS, when you made your mid 25 from 30, did you have to cut your shaft, replace shaft, or was there a 5" extender on the shaft?

[RickyR]

Before you spend a bunch of money to get your stiletto reworked, I can send you my prop to try. At least it will give you a baseline to see where you need to go. Like I said in my email, you need less diameter and to be consistent when testing them chaning pitchkeeping diameter, changing diameter keeping pitch- only change one thing at a time.



Thanks for the offer, I may ask you to do this, if the prop shop doesn't have that diameter for me to borrow. This is the first time I have ever used this particular shop, and he seems very willing to let me try his props, and even offered for me to use one of his newer ones when we get real close.
He seems to think that as the speed rises, I may get more r's too... He also said, to call him first before coming, and he would " play " with my prop while I wait..
When I get back from the mountains this weekend, I can focus on my boat.








PS, when you made your mid 25 from 30, did you have to cut your shaft, replace shaft, or was there a 5" extender on the shaft?

At the time, I didn't know my crank was bad, so we cut it at the gap area near the bottom of the steering tube. We shortened the shaft on the lower unit side, then tig welded a coupler to the shaft.
I drilled out the center of the coupler that I had, and used an older shifter bottom side (ebay) of about 4".
The measurements were exactly 5".. This was all done in that little gap area. My buddy is a great welder, and did an awesome job. But later I had to remove the powerhead anyway..:mad:

Thanks, Ricky...