NeverEndn

I bought a 1996 35ft Fountain Lightning step hull last year, it came with generally stock 500 HP's that made 515hp on the dyno. Well put it this way i got screwed over from the guy who i bought it off of with the motors giving me troubles the whole year. The boat did 80mph on GPS dead nutz. Well the motors were ripped apart to find out the water lines and most of the internals and carbs were rotted out and just guck and all kinds of bad things were inside these things. Eitherway , i had the motors rebuilt just got my numbers back today, and they made 701bhp and 701 tq. So that being said im currently looking getting a set of Bravo 30P labbed props and some CMI E tops for it. My main question is what kinda of speeds am i looking at hitting. A friend of mine had the same boat a year newer , except he had imco 2" shorties on it and 60hp less per motor and he went 88mph . So im hoping im in that range , what do you guys think? Will i break 90's or no. The drives are Bravo 1's in which im pretty sure those are maxed out for power , correct? Thanks guys look forward to using this site quite often

Smarty

How many rpms do plan on turning with 30" props? I would guess you would need at least 34" Bravos, if not 36" Bravos if you are really making 700+hp. If you are spinning 34" Bravos above 5200 rpm you will be 90+ mph.

Young Performance

If the hp numbers are accurate (both before and after the rebuild) then you picked up almost 200 hp. That should translate into about a 12-14 mph increase in speed. There is no exact science as to how a boat will react with more power and there are so many variables. A good rule of thumb for your boat is that you will need approx. 13-15 hp per 1 mph increase in speed. Again, every boat is different....some need only 12 hp and some need as much as 20 hp/mph increase. Your boat should fall in the 13-15 hp neighborhood. Good luck with it. Give me a shout if I can help in any way.
Eddie

offshoredrillin

also check here in the fountain section, use the search function and there is a pretty good chance that you can get real close with some answers. there is alot of those boats out there so I'm pretty sure someone has some info.

Skullkrusher

Not sure why you think you got screwed over. You bought a thirteen year old boat. I'll bet you paid a little bit less than what a brand new boat costs. There is a reason for that.

t500hps

, but most 13 year old cars look and run brand new???

700HP and TQ is over the ratings of the XR's....and that would be stout out of a 502 based 500 motor. Plan on buying drives soon as replacements, might as well run those till they blow (which probably won't be long).


(BTW:i've got 630hp, rarely run over 3,500-3,800 and blew an XR in 2 years)

H2Xmark

if your boat won't hit 90 with 700 hp then something is really wrong, like the hull is not straight, your drives are way to deep and or wrong props, also raw water cooled motors take a beating with corrosion and electrolyses. new motors if not taken well care of by flushing and maintenance will look like crap on the inside with time. sounds like you have a nice boat there, have fun with it and welcome to the board.

offshoredrillin

depends on how the seller represented the boat... fresh rebuilds etc etc...

NeverEndn

Well the props that were on it with the stock setup were labbed 28P, i planned on trying a set of 32P or even 34's not sure yet , the motors arent even in the boat yet. But i spun the 28P right to 5200-5300RPM almost to the rev limiter. The new setups RPMs are much higher i think it was around 5600-5800RPM ill have the dyno sheets this week.

NeverEndn

Yes i realize i paid less for it , due to the boat being older but the story really is too long to explain, but when someone advertises the boat as fresh water not SALT! also that it had freshly built motors in it with warranty and 10hrs on them and documents to proove it and the boat ran when i bought it, then blew up 2 days after. Ya thats being screwed over. Had the motors pulled after to find severe corrsion from salt sitting in it the internals for months. First problem : cracked head, blow starter, rotted out oil cooler, cracked exhaust manifold and intake manifold. The list goes on!. So i drive the motors down to where this warranty was to find out NO warranty, they claimed it was the sellers fault not theres lol! i cud go on but thats just the tip, eitherway the motors are good now and the seller is being sued! So u can buy things that are older and run great, not everything is crap just cuz its not 2 years old.