Bravo 3 Questions

[boatingedge]

Hi Guys,
I am looking to replace my Bravo III drive due to corrosion issues on the lower unit. I have fixed the corrosion issue so it shouldn't occur again, however my questions are regarding the replacement drive. I am not able to remove the drive as it is currently in the water, so I was hoping someone could tell me what the gear ratio of the drive most likely is. It is on a 1996 Maxum 2700 SCR (sport cruiser) and has a 7.4L 300 hp carb engine. I have access to a drive that is a 2.2 ratio. Will that work?
I was also wondering if the newer style bravo IIIs swap out with the older style units. The newer style being the type that has the two anodes over the prop and the slanted back instead of the straighter back with only
Thanks as always for your help

 

[HT32BSX115]

Re: Bravo 3 Questions

It is on a 1996 Maxum 2700 SCR (sport cruiser) and has a 7.4L 300 hp carb engine. I have access to a drive that is a 2.2 ratio. Will that work?

Howdy,

The easy way to know what the drive is would be to look at it and find the ratio on the "sticker".

If you couldn't do that you could remove the top cap and count teeth but in reality, you have either a 2.20:1 or 2.00: 1 drive.

Either will work except if you have one and you get the "other", your current props will be slightly "off".

It's more likely that you have a 2.20:1 anyway. The lower ratios are usually put on the bigger boats.

You also might be able to predict what you have using a prop slip calculator.

http://www.go-fast.com/Prop_Slip_Calculator.htm

Plug in the numbers (ratio, RPM, 12% slip) and see if the predicted speeds approximate what you get at those RPM.

AFAIK, the newer Bravos will bolt right up to your gimbal (and mine!)

I have a 1.81:1 by the way.....


Cheers,

Rick

 

[boatingedge]

Re: Bravo 3 Questions

Thanks Rick!!!

 

[TilliamWe]

Re: Bravo 3 Questions

Do you happen to know what pitch propset you have? If you do, I might have a better guess for you, as I can't say for certain Rick is right about the 2.2.
I will say this, it's either a 2.0 or a 2.2.

 

[HT32BSX115]

Re: Bravo 3 Questions

Do you happen to know what pitch propset you have? If you do, I might have a better guess for you, as I can't say for certain Rick is right about the 2.2.
I will say this, it's either a 2.0 or a 2.2.

Seems the bigger boats have a 2.2 and the smaller ones have a 2.0..... I also think knowing the prop-set would help decide

My 21ft Four Winns works great with the 1.81

 

[boatingedge]

Re: Bravo 3 Questions

The propset that was on it when I bought it a few years ago was a 26 pitch althought I am not sure if the prior owner put them on or if it came that way from the factory. However I wasn't getting it to its WOT specs so I reduced it to a 22 pitch. If I do currently have a 2.0 ratio, going to 2.2 should help my hole shot more with the same props correct? If that is the case then I would prefer the 2.2 as it is a big heavy boat and sometimes difficult to get on plane when I have a few people on it.

 

[Pete104]

Re: Bravo 3 Questions

Take your engine, drive & transom serial numbers to a dealer. They can tell you what it was originally. Call Maxum with the HIN & they can tell you what you had/have.

 

[HT32BSX115]

Re: Bravo 3 Questions

The propset that was on it when I bought it a few years ago was a 26 pitch althought I am not sure if the prior owner put them on or if it came that way from the factory. However I wasn't getting it to its WOT specs so I reduced it to a 22 pitch. If I do currently have a 2.0 ratio, going to 2.2 should help my hole shot more with the same props correct? If that is the case then I would prefer the 2.2 as it is a big heavy boat and sometimes difficult to get on plane when I have a few people on it.

I am surprised that it had 26p props! Those are pretty "tall" for a boat that size! (27' right?)

If you now have a 2.0 drive and you go to a 2.20:1 drive it will improve your holeshot.

What max rpm (and speed) do you get now at WOT?

 

[TilliamWe]

Re: Bravo 3 Questions

With a 22p propset, assuming you aren't overreving at WOT, you have a 2.0 on there now. Going to a 2.2 might cause you to overrev.

 

[boatingedge]

Re: Bravo 3 Questions

I am surprised that it had 26p props! Those are pretty "tall" for a boat that size! (27' right?)

If you now have a 2.0 drive and you go to a 2.20:1 drive it will improve your holeshot.

What max rpm (and speed) do you get now at WOT?

Yes its about 27 or 28 feet depending on whether you count the swim platform. RPMs get to about 4200-4300 which is the low range of my WOT target of between 4200 and 4600. With nearly a full tank of gas (100 gallons) 30 gallon water tank, 15 gallon waste tank there is no way I get to WOT on my current setup if I have more than 4 adults on the boat.

I believe it gets to around 38mph at around 4200 rpm.

I would love to get to the WOT target with the load listed above so I am hoping the 2.2 will get me there (assuming I don't already have a 2.2.)

 

[TilliamWe]

Re: Bravo 3 Questions

Are you sure your engine is running right? Are you sure your tach is right? 300hp in a 7.4, even with a 2.0 drive, and 22p props should do better than 4300rpm. And how did the boat even plane with the 26s?

 

[boatingedge]

Re: Bravo 3 Questions

Are you sure your engine is running right? Are you sure your tach is right? 300hp in a 7.4, even with a 2.0 drive, and 22p props should do better than 4300rpm. And how did the boat even plane with the 26s?

As far as I know the engine is running good. Compression for all cylinders is within specs. The spark plugs are clean and I just rebuilt the carb earlier this year.
I beleive the tach is accurate as I hooked up a shop tach and it was very close to what the instrument tach said. However I only tested it at lower RPMs so I will check to see if it is accurate at higher RPMs as well.

 

[HT32BSX115]

Re: Bravo 3 Questions

However I only tested it at lower RPMs so I will check to see if it is accurate at higher RPMs as well.

The upper RPM is where tachs are usually inaccurate.