Prop Height on 24 Superboat?

[JohnR]

I just picked up a 1978 24 Superboat with a notched transom and I'm hanging my 20" Merc 250 EFI on it. The boat has a 15" set back and the motor has no low water pickups. I believe about 3 or 4 inches below the V is a good starting point. Can anyone confirm this for me?

Thanks.

[JohnR]

Anyone? I've got it about 4 below right now. I figure better to start low and work my way up.

[rockyone]

Are you coming to the bash with it?

[JohnR]

It doesn't look like it.

My son has a scouts thing that weekend and I miss one if the major ones every year to go to The Romp. If things change I'll give you a call. Hope you and Ang are doing well.

[vnemous]

John are you counting setback in the step as part of the 15"? We have Georges 24 at 2" below on a 6" setback no notch. 4" below v that far back is probably too deep in my opinion.

[JohnR]

That is not including the notch, Mike. I'd say it's probably 5 more inches with adding the notch. I'm at work until 7 so I won't be able to measure right now. Did George have any sort of low water pickups? Mine only has the ones on the sides but the top 4 on each side are capped off. It's relatively easy to raise it to 1 below as it sits do I can raise it when I get it on the water if need be.

Thanks.

John

[85nova]

I run mine 1" below the the bottom, I also have a stepped hull and a torque master with the built in lwp

[JohnR]

Thanks. It was way too low and over propped (24 Trophy) the first trip out but it ran OK and stayed cool. Yesterday I raised it to about 1 inch below and definitely the wrong prop on a couple of different levels (too little pitch, too little diameter, 19 Laser 2) but as soon as I started trimming it up I ran into temperature issues so we called it a day and relaxed at the sandbar for a few hours. A friend is going to let me try a 21 Mirage and I'm going to drop the motor an inch and see how it likes that.

What prop are you using? Not so much concerned with pitch as much as model. If the Mirage works OK I think a similar pitch Tempest or Raker might be a good fit.

Thanks.

[85nova]

My every day prop is a 24p bravo, they seem to like the bigger diameter props and they don't like over the hub props, I've been told that a tempest works good on them just never tried one yet

[JohnR]

24? What motor are you runnin to turn that?

[transomstand]

24? What motor are you runnin to turn that?

Don't forget, it's not just the motor. It's also the lower unit gear ratio.

[JohnR]

Yeah but if he's got a Torquemaster the most it could be is 1.75, no?

This is on a 24 Super not a 21, right?

[85nova]

It's a 300xs, 1.75 gears, I can get it to spin a 28p 4 blade et if im light on fuel and have my girlfriends crap out of the boat yes it's a 24

[JohnR]

OK. That explains it somewhat then.

My wife, my son, and I, 70 gallons of fuel, our crap, and a full cooler and it was like "absolutely not" when I tried to plane with a 23 Bravo Saturday. The week before with a 24 Trophy it did it but grudgingly. Probably the smaller diameter, smaller blades, and over the hub exhaust that got it to actually plane. Hopefully I can get my hands on the 21 Mirage by this coming weekend. I think something around that pitch will be decent but I think a Tempest will be better since it has more rake and I'm guessing I'll need all the bow lift I can get.

[Karsten]

While I know very little about props I was told to get more lift and keep the bow down to go with a 4 Blade SS. I found a used MI Wheel Apollo 20P and what a difference that made over the aluminum 17P 3 blade. The boat ride flat, planes better and the controls are a lot more responsive. Next is the jack plate and try out a 22P Apollo I found and then a 23P MI Wheel ballistic performance prop.

Just tossing that out there.

Karsten