What are my odds?
 

Ok, so Im in the process of putting a roots on my 502, nothing radical but from everything I've been told "its only a matter of time before my Bravo XR will go"! I've read the forums where some people have had no problems while others didn't last 10 hrs, I understand you just don't know. My plans were to put blower on this winter, take it really easy on the bravo all summer and wait till next winter to upgrade to something stronger. But damn! After looking at the cost$$$$ of other lower units, I dont know if I'll have the money saved up by next winter or be wanting to fork out that much $$! Those damn things aren't cheap!! So Im asking you guys with experience in Bravo failers........when yours finally went....1) Was it a complete loss or did you just break something and had to rebuild? 2) How much did that cost ya? 3) Did you rebuild with upgraded parts? 4) Did it just break again? How many times have you rebuilt same unit? 5) Etc.

well I run about 750hp thru a stock bravo 1, run a drive shower and royal purple lube, just don't hammer getting on plane and watch getting airborne with it....been ok for 2 seasons so far...just have to be carefull....

Roots blowers make a lot of torque down low, that is hard on the Bravo drive. Prochargers come on a bit softer in the lower rpms and helps drive life a bit. XR upper gear sets are prone to breakage. When a tooth snaps off, it can, at times make a mess of things! It is a crap shoot at best with them. With the helical gears if you dont over power the teeth, they will last a long time. But torque is a killer on them. Accelerating through the mid range needs to be gentle. A wet hull and too much torque is not good. Once you get the boat lightened up, the drive can better handle the power..
Hope that helps.
Dick

Running 738lbft of torque. Broke a vertical shaft on an XR about 8 hours after I bought the boat. Running around 3,000 rpm's. Totally rebuilt the XR with all the upgraded parts. All new shafts, gears that were Cryo treated... 12 hours broke a tooth off the XR upper gear and cracked the upper case... Total rebuild again but with XZ gears. Lasted 2.5 hours and tore the pinion gear to pieces. Found it was a soft pinion gear right from Mercury. They gave a replacement set (back to XR's) and I still did another full rebuilt again with Cryo gears, new bearings, clutch shaft... and that cost was out of my pocket except for the gears. The drive is sitting in my garage with zero hours and I bought a used Bmax HT and rebuilt it. Put on 25 hours last season and feel good about the Bmax with no issues.
A light boat with a roots style blower and an XR will hold up with easy throttle use but with a 29' single engine it's going to break with that much torque.
Mr Gadgets is right about the wet hull/torque. Broke mine between 3,000 and 3,500 rpm's every time.

What do you mean by "wet hull"? And are Bmax a direct replacement for a bravo? Were you able to use all the same steering rigging? Prop?

Having a reliable running boat is sometimes more fun then a fast boat that breaks down, or being worried about it breaking down all the time.

I personally would not chase the speed unless you have the cashola to do it properly. No offense. I have been there and been very unhappy sitting on land with a broken boat.

Your drive will break, or wear out. Hard to give a accurate estimate since 1 or 2 seasons for one guy is the same as 4 or 5 seasons to the next.

Cost to rebuild a broken drive could be anywhere from $2000 to $8000, and it could happen on average of every 20 to 80 hours in a set up like yours. For my boat I have to rebuild the pair every summer! Sucks!

B-Max are good drives but still use XR lower gears. Johns customer service is excellent. They cost around 13k new.

SCX would be another choice, around the same price new also.

There is no option that is less expensive besides keeping your HP and TQ where its at and enjoying extra fuel money to go boating more often!

Not only will you have to save up for drive repairs and/or upgraded drive. You will also have to rebuild the engine to make it stronger. Eventually you will want even more speed, and more, and more, it never ends untill you choose to be satisfied with what you have. Why not choose to be satisfied now?

This makes the most sense to me, very wise information!!!!!

I'm running whipples on my 525's in a heavy boat with XR's and 5 blades. I change the drive oil and swap right for left at the end of the year. Two seasons, no problems including a bunch of Poker Runs.

i think allot has to do with how you use the sticks. Its not a drag boat, so I am very easy getting on plane and i do not slam the throttles at any time. Just roll it on and back off easy. Also, where I boat it very rarely launches completely out of the water, so the drive is not subject to massive, sudden torque.

Will they go? Probably at some point, but if I was really that worried about breakage I would have left them stock. I just love the performance sound of that supercharger whine and havng a Formula that can run as fast as it does!

Ran bravo X's on a 36 Baja outlaw (heavy and wet) with 500hps and 177 blowers. Never once lost a drive, but lost a few engines.

Keep in mind where you are when you ask this question.

OSO Rules

1. If you have any kind of bravo drive it will break, in fact it is probably already broken
2. If you add a supercharger be prepared to spend another $18k on engine internal upgrades or it will blow up in seconds, probably while idling
3. If your boat has been used in salt water, been parked near saltwater, or if anyone has eaten saltine crackers in the cabin it is shot, just toss it.
4. Nothing less than a 4500 series DRW truck should be used to tow your 29 ft down the block to the launch ramp, in case the trailer brakes go. Most boat towing accidents happen in the launch parking lot, so don't take stupid chances, insurance will not pay.

All kidding aside

Change the oil every 25 hrs, use the best oil possible made for your drive
Pull the upper rear cap and inspect the gears every 25 hrs
If you are spinning the drive LH find a stronger after market top cap. Right now there are a few billet ones on ebay at a good price

If you blow the upper, and do not have access to a great drive shop to inspect, you may consider replacing it with new or after market. The upper case can stretched fairly easy if the gears come apart. Causing premature failure for the next set....and a bad name for bravo's. This is why gear inspection is crucial, catching them before catastrophic failure is key

Wet hull!?
 

This may be a dumb question but, Once again "wet hull" is mentioned. Can someone explain this term? And I have been asking around the area here for someone to go through my lower unit before I re-install it, but not having much luck. Im thinking about just doing an inspection myself for obvious problems like gear teeth conditions but I ve never had one apart before. I feel like I am mechanically inclined enough, but just a visual inspection prob. not enough, is it?? Im guessing there are clearances that would need check too HUH?!

"Wet hull" referse to the convetinal flat bottom v-hull with no steps or notiched transom. In return comes alot more stress on your drive

Thanks! I do have a single step, so that should help a little.

If its Fountain that you are running you also have a notched transom and padded keel. Other than a cat, your are not going to find a more efficiant hull out there.:party-smiley-004:

You say "your are not going to find a more efficiant hull out there." BUT the damn thing is so heavy and hard to get on plain, that is my main reasoning for putting the supercharger on it.

Well, that, and they are cool as hell! lol AND that is motor, NOT motorS. 29' is alot of boat for one motor.

Exactly.....which makes your roots blower even better for the application. Your increased tq at low rpm from the blower will get you on plane twice as fast. It is amazing how much a blower helps a single engine boat plane.

Just don't nail it out of the hole, you should no longer need to go wide open to get it up.

I would be less concerned with the lower than the upper. Most lower failures are caused by upper failures.

Thats exactly what im thinking. And really glad to hear that! I want to be able to slowly roll into the throttle getting on plane. No more stabbing.

Yep, the upper is the weak link. I have the same boat as you, 29 fever with the single motor. With the motor upgrades done to the 575SCi I can get on plane with only 1/3 throttle.
A lot of guys break the drive around 3000-3500 rpm’s with it trimmed down and plowing in rough water (wet hull). Around that rpm is where the torque peaks and is hard on a drive.
Try All American Drive Service here in Michigan. Good guy to work with. Also Mr. Gadgets is the man.
It’s no fun standing on the beach or being towed in. Put extra cash aside for an SCX or Bmax first and you will be at ease without the feeling like you are going to break a drive every time you go out. “Been there done that”.
That’s what I should have done before I spent over 10k on rebuilding 3 Bravo’s.
The Bmax is almost a direct bolt on. Did mine in a weekend. The inside parts in the lower is the same as a Bravo but I never had any problems with the lowers. Cryo gears from the Bravo Shop and a good setup and you should not have any lower issues.

Thanks for your input. I've been hearing more about the Bmax drives and am thinking I need to start looking into them more. I full intend on an upgrade and that seems to be right up my alley. Seems that might be the best upgrade for the cost??

You need a different prop if that is what you're after. Its not a ski boat and its not going to jump on plane like one.

One of the things to keep in mind with fountains is , (from what i have taken) is majority of them are set up for top speed, your X dim may be a little high in order to achieve this. You wouldn't be the first fountain owner that has trouble getting up, but once it does it runs like a raped ape. check with some people that are knowledgeable about your hull just so you dont start throwing money add it. would a spacer help with coming up on plane? maybe a diff set of props? As Mr gadgets said, torque is what kills xr's. my boat is a heavy pig, but i have only broken a lower gear and that was at 472 hours. I guess my point would be is try a few things that address the problem, not the symptom.

I was informed about the fountians slow plaining before I even went to look at the boat and you are right about "raped ape", once the boat hits plane it takes off like you hit a NOS button! I guess I should clearify to everyone too that I do know there are plenty of other ways to help getting the boat on plane rather than spending the $ and installing a SC! BUT, I've been a gearhead my whole life and I cant leave anything stock and love HP and speed. I usaully am good too about upgrading the weak points 1st before up-ing the HP. Im just planning on running 4 lbs on this motor until I upgrade the lower unit.

I can understand being a Gearhead myself and how we love to improve everything! I love my Prochargers and love the speed also, but hate the cost and downtime! As long as you are aware then have at it and enjoy. Just would hate for you to not realize everything and get a bad taste for high performance boating, or get in over your head which causes you to get out of boating in general. Theres just something about once you have the speed if you end up not being able to afford it and have to step back down to a slower more reliable boat sometimes it just causes people to get out of boating all together.

Yes your engine will handle the blower for a while on mild boost. Just as long as your aware eventually you will either need or want to upgrade

Bravo drive will handle the added power for a while on mild boost. Just as long as your aware you will get sick and tired of babying the sticks even if it does not break.