Need Help 24' Superboat

[liwake]

I just bought a 2000 24' Stepbottom Superboat with a 225 mercury promax just rebuilt new pistons and cranks and new lower unit.


I took it out for the first time today and something is wrong because with myself and 4 others our max speed was 43(GPS).
The boat had 30gallons of gas in it and I would think we would reach about 60mph. The racing unit was replaced by a non-racing lower unit(talked to John coen and he said this shouldnt change the speed). The rebuilt motor has about 2 hours currently on it.


About 6500rpm at wot and spinning a Michigan wheel Apollo xhs A series
Prop Pitch=14x22

Anyone have any idea what's wrong?

[vnemous]

Bottom painted and dirty??? Hub shot? Not enough prop and on rev limiter? My buddys turning a 25p at about 56mph with his 225 opti.

[liwake]

It's not bottom painted, just compounded and waxed whole boat saturday. I'll check out the hub but I don't think it's shot, do you think I need more prop since I only have 22p

[mrpenguin]

Try a completely different prop. See if you can borrow a 24 or 26 pitch Mercury Trophy Plus prop. That will tell you if was just the prop or hub or if the engine is down on power.

[lightspeed]

Those Props Are Junk ,,Look For A Trophy plus ,,Take It Out By Yourself And See How It Runs ,They Dont Like All The Weight In Them ,,Meaning 5 Guys And 250 Lbs Of Fuel,,

[dnelson964]

It's not bottom painted, just compounded and waxed whole boat saturday. I'll check out the hub but I don't think it's shot, do you think I need more prop since I only have 22p

24 superboat, great boat, but is no light weight hull + 5 people = very heavy. Try larger diameter prop (14 3/4-15 1/4) w/ similar pitch and your slip #'s should do much better w/ better speeds. Maybe a Large barrel thru hub type to help the stern lift. JMO

Oh , if you waxed the bottom I would wipe that off.

Bravio I w/ pvs holes?

[Jamescole]

Yamaha's do pretty good on 24 SB's... not that your going to change your motor.. but a local to me 24 with a 300 yamaha 3.3 with a 27 t1 does 76 or 77.... and last july 1st long weekend 5 of us and the same set up we did 70.... must be the torque..

[liwake]

@nelson-I didn't wax bottom, only the sides

I'll see if I can borrow a Trophy plus prop, and I talked to John coen's son and he said that he's never seen a 24' superboat go under 60mph with a 225 so I think he might take a look at it

[Superbender]

Just so we are on the same page,you have two hrs on it and your spinning it up to 6500?

[liwake]

Just so we are on the same page,you have two hrs on it and your spinning it up to 6500?

fluctuating rpm's not going 6500 whole time, going from low-to-high rpm's since the motor is still being broken in

[ghost28]

First off go out and get at LEAST another 6-8 hours on it before spinning it anywhere near 6500rpm.....with that said that boat should be running a Tempst or a tropy wheel....My personal favorite being the tempest....most other wheel especially michigans and aftermarket other brands are garbage.....step 24s with outboards do not like trim the more you trim the slower you go....trim it level and thats it....that boat on its best day should run 62-64 with you alone and light on fuel....with 5 guys on board and fuel and whatever else you will be lucky to see 55.....my step 24 with a 250 spun a 24 tempest to the limiter at 5850 with me and my wife and 1/4 tank of fuel all the time and did 68 with a best of 69.9 with me alone and running on fumes...add two more people to the mix and some coolers and whatnot and best i would see was 62-63...

now with a 23 trophy plus it would also hit the limiter at 5850 but only ran 63 and some change on its best day....add 2-3 more people and fuel and 57ish was about it.....

moral to the story...get a real prop and break that poor motor in before you make junk.....not sure where you launch out of but if you are anywhere near tanner i would be glad to let you try a 25 tempest or a 25 trophy or a 23 mirage....and i could also show you how to trim it right cause trust me it isnt like any other boat when it comes to trimming....

[sausage pizza]

First off go out and get at LEAST another 6-8 hours on it before spinning it anywhere near 6500rpmsome coolers and whatnot and best i would see was 62-63...

....and i could also show you how to trim it right cause trust me it isnt like any other boat when it comes to trimming....you dont just hammer it and press a button to go faster...hummmmm interesting :rolleyes:

[ghost28]

you dont just hammer it and press a button to go faster...hummmmm interesting :rolleyes:

nope......during break in use of the fun button needs to be kept to a minimum......:reddevil:

[Brabender]

So good to see u posting again fat sausage

[rchevelle71]

All good advice above, Try the Trophy or tempest, or even a mirage plus, my 24 pantera non step ran 59 with a 225 25" fishing motor, 21" mirage plus, you should be doing better than that.

[speedman79]

Someone I knew years ago had an early 80's 24 superboat with a 225 Evinrude. That boat would do 64mph with 1 person or 4 :D.
Very consistent setup - not sure of the prop he ran but your boat should be doing over 60 regardless. I wouldn't go out with friends until its broken in - you're lugging the motor more to plane off...

[Superbender]

I like to glue corn flakes to the bottom to help aerate the hull,and if I get hungry later you can snack

[tux974]

I like to glue corn flakes to the bottom to help aerate the hull,and if I get hungry later you can snack

That is funny...does that mean to only test in the AM and with a gl of milk :confused:;):D:smiletest:

BTW liwake, take Ghost28 up on his offer, he has run in every 24 on LI and will give you some good and very solid advice.....:thumbsup:

[Fandango]

Like ghost said...tempest or trophy, (and I know someone with a 24' non step who is swearing by the Merc Rev 4). then go hook up the kill switch, and just take your time getting to know the boat. You dont need to trim it much, its a fun boat, but like anything performance related, you just need to respect it. I also found it hates taking wakes on the side, so get a good line on boat wakes, and it will tend to lean into a crosswind as well. Enjoy.....and take your time.

[ghost28]

I like to glue corn flakes to the bottom to help aerate the hull,and if I get hungry later you can snack

MMMMMMM Corn flakes......However i would prefer frosted flakes myself.......:cheers:

[87starflite]

captain crunch works better but only the peanut butter ones

[RobF]

I like to glue corn flakes to the bottom to help aerate the hull,and if I get hungry later you can snack


remove the wax gain at least .25 mph

I bet the corn flakes gives you 10+

[Billy Sedman]

Find another promax and hang twins on it!!!!

[bskater18]

Hey guys i just got my new to me 24 Superboat out for the first time on sunday and had a blast. i have an old school twin 200 mecr set up with 26" choppers. it takes off great and gets to 65mph fast.
http://i50.tinypic.com/2mpn442.jpg
http://i45.tinypic.com/2e4zrwo.jpg
I took if offshore to blast around in the 2-3's. it lands nice!! :thumbsup:
I don't know how to rotate the bottm pic. help. thx

[Chaz]

Find another promax and hang twins on it!!!!

Thats kinda what I was thinkin. That boat is gettin big for just one 2.5 when you are talkin top end numbers ..

[bohnrods]

nope......during break in use of the fun button needs to be kept to a minimum......:reddevil:
Maybe, Instead of breaking it in, He could add nitrous! Anybody on the great south bay remember a little yellow `67 sweet sixteen running out of Bluepoint?

[vnemous]

Ran Rice Crispies on Fullers 24 this weekend. The Snap, Crackle, Pop really seems to free this hull up:D

[baja200merk]

I worked on my boss' 24 superboat w/175 pro xs in nyc harbor crappy conditions motor was way to high almost full tank went 58mph. I'm sure it had low 60s in it if it wasnt choppy as hell from ferrys.

[rchevelle71]

I worked on my boss' 24 superboat w/175 pro xs in nyc harbor crappy conditions motor was way to high almost full tank went 58mph. I'm sure it had low 60s in it if it wasnt choppy as hell from ferrys.

58 with a 175?? musta been turning some RPM

[baja200merk]

It would go into guardian after a short blast putting the 21 trophy on the limiter I'd assume. We know mercury pro xs hp ratings are a bit low.

Maybe it was 54 or 56, I will see if I still have the picture of the GPS on my phone. I just remember I was pissed cause it was as fast as my 21 paramount was with a 200 on it.

[JrCRXHF]

I want to watch what you guys come up with because i have not go the speed out of my twister 24 that i thought i should.

[Billy Sedman]

Imo I think a 2.5 would get its arse worked off on a boat that size!!

[mrpenguin]

I would wage the "rebuild" job may not be up spec also. It could be a dremal port job with scotch bright pad honing.

[baja200merk]

Imo I think a 2.5 would get its arse worked off on a boat that size!!

Prop accordingly, this pro xs made light work of the one I worked on 40hrs a week under the brooklyn bridge.

[bskater18]

Maybe, Instead of breaking it in, He could add nitrous! Anybody on the great south bay remember a little yellow `67 sweet sixteen running out of Bluepoint?

yes was a guy i use to work with on the bay back in the day. thats a classic and was in very good condition in the summer of '96. that was the last time i saw it.

[Part-Time]

I don't remember on what forum I found this, but it sure helps when trying to find the right prop.
http://www.rbbi.com/folders/prop/propcalc.htm

[liwake]

Thanks for all the help so far everyone.

I found out the new lower unit gear ratio is a 2.1(is this good/bad?) and im spinning 6000rpms not 6500 at wot.

So what prop pitch should I be getting when I get a new prop? I've been told 27 by someone and 24 by another, what do you guys think?

[87starflite]

2:1 gearcase is part of your problem. that gear ratio isnt going to allow you to yield the top end numbers you may be seeking. id look into trying to test a different case

[baja200merk]

Just put a bigger wheel on it for now to make up for the lower gear ratio. Will be cheaper to buy a used 23 tempest/trophy or mirage then buy a case (unless you sell your case you could break even). The 2.5 opti on the one I worked on had a 21 trophy with a 1.87 the mathematical difference between 2:1 and 1.87 is 2in of pitch. You would be fine with a 23 :thumbsup:

Some people like the bigger gear for 2.5s on heavier boats. I know a guy who likes 2:1 in his 28 skater with 280s cause he swears it helps it accelerate.

[BUD]

kevin, wasnt the 24 sb in ny a center console? id love to find one of those

[baja200merk]

No it wasnt. I would love a light step bottom CC superboat blow the doors off concepts and have a better ride :thumbsup:

[liwake]

Baja200 can you clear up your PM box so I can send you a message asking some questions?

Also guys which prop is more ideal for speed, Tempest or Trophy Plus ?

[ghost28]

Baja200 can you clear up your PM box so I can send you a message asking some questions?

Also guys which prop is more ideal for speed, Tempest or Trophy Plus ?

i guess you didnt read my post.....On a stepped 24 the Tempest is faster all across the board....Midrange and top end....the trophy is decent all around IMHO

[liwake]

i guess you didnt read my post.....On a stepped 24 the Tempest is faster all across the board....Midrange and top end....the trophy is decent all around IMHO

Sorry Ghost28, did not see your original post, thanks for the info. What pitch do you think would be the best for me with a 2.1 gear ratio in the lower unit? I was told 27 and also was told 24 but since you have a 24step I'd like to see your opinion.

P.s. will keep the offer on trying out the props and trim in mind

[baja200merk]

Baja200 can you clear up your PM box so I can send you a message asking some questions?

Also guys which prop is more ideal for speed, Tempest or Trophy Plus ?

I got the email on my phone that my inbox was full sorry just got back from the shop.

I will be the first to tell you I have minimal experience with superboats. I grew up in long island and have wanted a superboat since I got my boaters license at 10 but the wrong island boys are the ones you need to be sending a PM to. I have driven them but never had my hands on one long enough to convince myself I have it figured out. Now if you want to talk about triple digit action or a tunnel I might be able to help in some way, but superboats listen to these guys, PM them you will go faster.


The trophy seems to work well on the superboats but it was worthless on my paramount. Each boat is different.

[BUSHWACKER]

Try www.offshoreonly.com (http://www.offshoreonly.com) and www.superboatonline.com (http://www.superboatonline.com) for setup info on your Superboat.

[Brabender]

Trust ghost he knows. Why send the guy all over Gods creation, when the experienced good info giver is offering his help. Once you get past the shiny dome, he's a good guy

[OrangeCrush]

Trust ghost he knows. Why send the guy all over Gods creation, when the experienced good info giver is offering his help. Once you get past the shiny dome, he's a good guy Ill" second that . He knows his stuff,always answered my questions

[liwake]

Baja I wanted to ask you some questions about the gear ratios rather then directly about the superboat itself since it seems like you know what your talking about when it comes to the gear ratio.
I was going to PM you this put I will just post the questions in the reply so anyone feel free to help pls

-Baja explained that to make up for the lower gear ratio to get a bigger prop pitch. Im not to familiar about gear ratios...could you explain by what you mean when you say 2.1 is a lower gear ratio compared to the norm 1.87 on a 2.5.......what does the "lower" gear ratio affect exacly?rpm?

-If it is rpm how will a bigger prop pitch make up for the lower gear ratio compared to the higher since a prop doesn't affect rpm?

-And if a bigger prop pitch helps it, wouldn't a bigger prop pitch then just a 23 be more ideal...like say a 25-27?

[baja200merk]

Baja I wanted to ask you some questions about the gear ratios rather then directly about the superboat itself since it seems like you know what your talking about when it comes to the gear ratio.
I was going to PM you this put I will just post the questions in the reply so anyone feel free to help pls

-Baja explained that to make up for the lower gear ratio to get a bigger prop pitch. Im not to familiar about gear ratios...could you explain by what you mean when you say 2.1 is a lower gear ratio compared to the norm 1.87 on a 2.5.......what does the "lower" gear ratio affect exacly?rpm?

-If it is rpm how will a bigger prop pitch make up for the lower gear ratio compared to the higher since a prop doesn't affect rpm?

-And if a bigger prop pitch helps it, wouldn't a bigger prop pitch then just a 23 be more ideal...like say a 25-27?

Mathematically the difference between 2:1 and 1.87 at 6k rpm is around 400 rpm. You can use a prop to make up the difference, prop calculator says you would need to run a 24.6p with the 2:1 to go the same speed as a 1.87 with a 23. So 24-25 would be a good place to start. Math works in a perfect world, props, conditions, load, etc. are some of the hundred variables. You will just have to try some props.

[liwake]

Mathematically the difference between 2:1 and 1.87 at 6k rpm is around 400 rpm. You can use a prop to make up the difference, prop calculator says you would need to run a 24.6p with the 2:1 to go the same speed as a 1.87 with a 23. So 24-25 would be a good place to start. Math works in a perfect world, props, conditions, load, etc. are some of the hundred variables. You will just have to try some props.

Sounds good, would having an even higher pitch prop such as a 27 pitch make it even faster?

[jerry]

go to your local gas station , get a gallon of fresh gas . go home pour it all over the boat , and well guess you know the rest , than go buy a progression hahahahahaha

[ghost28]

go to your local gas station , get a gallon of fresh gas . go home pour it all over the boat , and well guess you know the rest , than go buy a progression hahahahahaha

Probably the best advice here so far....even better than the cornflakes advice.....

Try a 25 tempest with the 2:1.....i bet that would put you close to where you should be....also motor height is gonna play in your prop selection as well....Personally on a stepped 24 unless you have big power i like the motor a little deep but i have always run 3.0 liter motors on my 24.....lets not confuse anything though and lets get you broken in and then find a prop that works for you and then fine tune with engine height.....