rotax406

I have a 88 240 with a 540 in it wot labbed 26 bravo runs 74 at 5650rpm with a stock bravo 28 it does 72 at 5100 both props are pushing 19percent slip even at mid range it is a stock x dimension with a standard bravo drive 1.5 ratio the boat will run these speeds with 75 gal if fuel fully geared for the day and 5 180 # adults same slip numbers but is stable empty it gets really bad chine walk it would prob go alittle faster but I cant keep it under control its a very exciting 74 lol and yes its on GPS and also I have no idea what power this motor makes it is a motor I threw together just to get by till I get my other 540 finished up I am new to fast boats any good advice is appreciated

BBCLiberator

iTrader: (2)

Sounds like you think you have a 1.5 drive ratio, when you really have a 1.65...just a guess. If you are turning that thing to those RPM's and speed there is absolutely no way you have that much slip unless that boat is wickedly effected by load, but that seems extreme.

My money is on the 1.65 drive ratio. Using that ratio puts you about 12-13%, which makes perfect sense. I bet with a lighter load you would see a 1-2% decrease, into the 11% range'ish.

Baja Rooster

iTrader: (1)

I bought a boat with a 1.5 ratio and was chasing bad slip numbers, but pulled the outdrive and someone etched that they changed it to 1.65.

Mr Maine

Aren't Bravo props actually about 1 inch less of pitch? Also, do you think you are maybe over trimming a bit causing the prop to blow out a couple hundred rpm, but still maintain the speed?

ezstriper

more of the hull than the prop...want to go fast put the 540 in something else...sorry

Black Baja

iTrader: (2)

My buddies 240 with a 540 and a 4150 carb goes 85mph. Mine went mid 90's with a 540 when it hit 93 I stopped looking at the GPs.

rotax406

1.65 could be the case and as far as other hulls go give me some options that are affordable and have a sleepable cabin that will handle some rough water also as far as 93 mph goes I would like to know what u did to the hull for handling because Eddie fountain could not hold on to mine at 93 lol and also that is impressive but what is your set up seriously motor wise n/a or charged also what is your buddies set up also are you running a shortly and what for drive

articfriends

iTrader: (1)

Speed sounds about right for a typical Baja, in comparison My 272 runs 74 to 76 with 26 pitch labbed at 5400 to 5600 with blower belt off, prop slip numbers on mine have always been high, got them lower with different props and all that did was slow it down, and kill acceleration, fwiw. My guess would be about 550- 600hp unless the 240 goes much faster than the 25 and 272 with same or lesshp.

Black Baja

iTrader: (2)

His is n/a 540 750hp. Mine was a procharger 540. Mine was like a rocket and would literally jump out of the water if you nailed it out of the hole. When on plane if you nailed it it would lay all the way over on the port side of the v I rode that side of the v down the river many times. It was funny at first then got annoying. Unfortunately b4 I got the completely dialed in I ran out the river into the bay it started raining I had my uncle with me and decided to turn around. There is a very well marked channel and as usually the channel was full of crab pots (not supposed to be) I got out of the channel and was going slow not paying attention and hit a rock pile. It scraped the bottom pretty good and broke the drive in half. That was the end of the Baja. The boat would have probably gone over 100. I never had much trouble running 70-80 mph. When I had the 496 in it ran 75 and I would push it wide open and run everywhere like that. We boat in a shallow bay. It's often small craft advisory all the stuff we get around here is pretty close together it's easier running faster that slower but it does beat the boat up. The last time out in my Donzi last year a broke the console holding the controls in the boat. The throttle ended up on top of the gas tank.

Black Baja

iTrader: (2)

We both ran -2 drives. Both boats liked a lot of trim.