Bravo III is slipping as engine RPMs increase.

RegalMania · Jul 24, 2009

I am new to this, so help me out if there is more information that I need to provide. I have a 2004 Regal 2400 with a 350 Mag and a Bravo III outdrive. The boat/ motor/ drive has about 75 hours on it, everything is original equipment. Last Saturday was the first time that I experienced this, the prior weekend showed no signs of an issue. When I engage the drive at idle speeds, the boat moves and tracks as it always has. As I throttle the engine up, the boat increases in speed but at a far less rate than previously, i.e. at 4800 RPM I am cruising at about 20MPH rather than the 50 MPH the prior weekend. The boat still moves so the drive is not completely broken, I just am not sure what the problem is. I have it at the local Regal dealer right now and they are scratching their heads based on my description (they have not yet torn into the boat to see what they find). I am asking for help for a few reasons: 1) to ensure that they diagnose and correct the real problem 2) to see if there is something that i can do to prevent this from happening again 3) to start this forum so that if there are others out there with the same issue, they too can benefit from the answer. Any help you can provide would be great. Thank you.

bhammer · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

I don't know the BIII drive, is it possible to have a spun hub on one of the props? The only other thought would be the engine coupler.

RegalMania · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

Thanks for the reply. I have had a couple of people tell me about the spun hub, but from what I have found online, the B3s don't have the spun hub problem of their single prop cousins (different hub design). I have heard the coupler issue before too. What would cause premature failure of the coupler? Like I said, the boat only has 75 hrs on it. If it is in fact the coupler, that will be an EXPENSIVE repair as i have heard also that the coupler repair entails pulling the motor. Ouch.

jaxnjil · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

no spun hub on a BII. they use a solid hub in both props.if not a problem in cone clutch then just about has to be spun engine coupler
possible but these are massive couplers.

sdoomaha · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

Buddy has a 99 Lund Tyee Grand Sport 1950 with the carbed 350 Alpha drive in it. Bought new, used sparingly....5 years ago lost the coupler with less than 80 hours on the motor.

Boat was delivered to the dealer with the lower unit not attached, was part of the prep the dealer did, and the dealer obviously did a very poor job of alignment to "cook" the coupler that quickly.

Best of Luck

lc1192 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

I have a 140 mercruiser with an alpha one drive that did the same thing, only there was a pretty good vibration at around 2200rpm. I have yet to fix it, but alot of people tell me that it is the u joints in the outdrive. you might check that.

TilliamWe · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

Coupler or failure of the clutches in the drive, or possibly a shift cable wearing out, not allowing the clutches to engage the gears all the way.

What about an obstruction ahead of the props causing them to ventilate?

"Techinically" the B3 has a separate hub, but it's welded as part of the manufacturing process. If you somehow broke one loose, it would be visibly apparent. But I have seen some pretty bashed up B3 props that didn't break at the hub. So it's 99.9% not the props.

"Boat was delivered to the dealer with the lower unit not attached, was part of the prep the dealer did, and the dealer obviously did a very poor job of alignment to "cook" the coupler that quickly. "

Nope, not true. The manufacturer did something wrong when they installed the engine. Or your friend never greased the coupler. Installing the outdrive does not align it. The alignment is the motor to transom plate, not the outdrive itself. You can remove and re-install an outdrive a million times and never once affect the alignment.

HT32BSX115 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

I am asking for help for a few reasons: 1) to ensure that they diagnose and correct the real problem 2) to see if there is something that i can do to prevent this from happening again

The above member is correct. There are NO "rubber hubs" in Bravo III props. It's all "metal-metal".

If there's no other grinding noises (indicating that it's internal to the drive) it's almost exclusively the coupler.

This may happen if the drive isn't removed and the alignment checked/adjusted regularly. (Mercury suggests every 100hrs or every year which ever occurs first)

If the coupler is indeed "spun" the dealer will need to remove the drive and remove the engine to replace it.

It's not gonna be cheap.

Sorry about that.

Rick

sdoomaha · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

TilliamWe please increase my learning as I am only a driveway mechanic.

I was under the impression whenever you pull and reinstall your outdrive, you always want to double check the alignment. Using the alignment tool when reinstalling the outdive tells you if everything is lined up properly, if not the alignment gets adjusted at the engine.

If the dealer would have checked the alignment before installing the outdrive, wouldn't they have noticed that it was out of alignment and shouldn't they have adjusted the engine accordingly? Is it not common practice for a dealer to check alignment when installing the drive in case the engine "shifted" during shipment?

Thanks for sharing the knowledge....

jaxnjil · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

regal; you have two gears that are located on top and on the bottom of the input drive shaft and mesh with gears on upper and lower gear assembly

these have a cupped shaped taper on the inside of each gear and the tapers face each other. your drive changes direction by way of a sleeve that locks to lower gear shaft and fits in these tapers or clutch as it is called. stopping in the center leaves you in neutral and reverse and forward is gained by clutch moving either up or down on the lower gear shaft. it has a friction material bonded to the cone on the top and bottom to to engage the tapers in the upper and lower gears and not slip

as TW stated the lower cable could be out of adjustment or stretched
and not moving the clutch up or down enough and letting it slip

as these two components -- the cone clutch and engine coupler-- are the only place in this drive system that don't make a gear to gear lock up that would be the most likely places to check. the lower shift cable would be my first to check and if it isn't out of adjustment or bad then the coupler.if the coupler is bad it will you will need to pull the motor to repair.
at 75 hours i would still think its the lower cable

HT32BSX115 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

whenever you pull and reinstall your outdrive, you always want to double check the alignment.

Absolutely true.

I cannot believe a dealer would not check the alignment if they received a boat with the drive removed.

Isn't this a 2004 boat?........ It's possible that the drive has NEVER been removed and the alignment checked in those 5 years.

RegalMania · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

That is correct, there is no other grinding or knocking. The drive engages just like it always has, nice and smoothly. I know the Alpha one has a hard engage, but I have not found that with the B3. The engine runs very smooth as well, no hesitation or anything. As for abstruction causing cavitation, I wish that was the case. That would be an easy fix and would save me a few bucks on repairs.

As for the engine being out of alignment, is that something that could slowly cause the coupler to decline? As i have stated, the boat has 75 hours on it and has never had any trauma to the drive.

You guys are great, thanks for all of the advise. At least I will be able to speak intelligently to the dealer.

RegalMania · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

Jax: Thanks for the heads up on the cable! I will ensure that the cable is the first thing checked by the shop...PRIOR to pulling the motor. Thanks again!

HT32BSX115 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

As for the engine being out of alignment, is that something that could slowly cause the coupler to decline? As i have stated, the boat has 75 hours on it and has never had any trauma to the drive.

Well yes and no. The coupler will slowly become damaged but they usually fail all at once. There's not much in between.

When mine failed the inside (aluminum) splines in the became stripped almost like someone drilled them out with a drill press. The (steel) yoke was undamaged.

For a short time the day before it intermittently "slipped" like it was slipping out of gear a couple of times but kept running.

The next day when I put it in gear it slipped continuously. End of story.

If the rubber "dough-nut" part of the coupler fails it's usually all at once too.....and there's sometimes a smell of burning rubber and black rubber powder in the bilge at the back. It probably depends on how hard you're running it at the time......

If you have none of those symptoms it could be in the drive but they usually don't "slip" smoothly ...... It's usually "all or nothing" too.

TilliamWe · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

sdoomaha said:
TilliamWe please increase my learning as I am only a driveway mechanic.

I was under the impression whenever you pull and reinstall your outdrive, you always want to double check the alignment. Using the alignment tool when reinstalling the outdive tells you if everything is lined up properly, if not the alignment gets adjusted at the engine.

If the dealer would have checked the alignment before installing the outdrive, wouldn't they have noticed that it was out of alignment and shouldn't they have adjusted the engine accordingly? Is it not common practice for a dealer to check alignment when installing the drive in case the engine "shifted" during shipment?

Thanks for sharing the knowledge....

That is how you check alignment, yes. But at the factory, Mercury and Volvo check the alignment. If the motor "shifts" during transport, then the boat has a SERIOUS problem. So, no a dealer need not check the alignment, when installing the outdrive on a brand new boat.

Regal, some folks who have spun an engine coupler have smelled the rubber hub melting out of them. And some can even see down the backside of their engine and see the melting rubber. Can/could you do either of these? But I also agree, spun couplers tend to be gone all at one, and there's no getting any forward movement out of them.

RegalMania · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

No, there are no signs of visible damage on the engine nor in the bilge area. There is no oil residue or burnt rubber anywhere to be found. There is definately forward movement from the boat. Would the lower cable being out of adjustment be a more likely scenario than the coupler given that the movement didn'e cease completely?

HT32BSX115 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

But at the factory, Mercury and Volvo check the alignment.

This may be irrelevant but "Mercury and Volvo" don't check the alignment at any factory.

Boat manufacturers like Sea Ray, Bayliner, (which may be even be owned by Mercury parent co Brunswick), Maxxum, and all the others......etc buy engines and drives FROM Mercury and Volvo.

The engines and drives are installed (and aligned) by the installers at the respective boat manufacturing facilities.

That's not to say that their installers are not trained to correctly install and align the engines. (AND it's really NOT rocket science anyway....)

But if I owned a retail boat sales facility and I received a boat with the drives removed I would make it a point to shove an alignment tool in the hole before I bolted the drives back on.

AND I would document it as such regardless of what I was told by the "Factory"

That's just good customer service....

TilliamWe · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

Yes, please forgive me, I meant to say the "manufacturer" checks the alignment. I mistyped the engine manufacturers names in that spot. Yes, the boatbuilder set the alignment at their factory.

HT32BSX115 · Jul 24, 2009

Re: Bravo III is slipping as engine RPMs increase.

TilliamWe said:
Yes, please forgive me, I meant to say the "manufacturer" checks the alignment. I mistyped the engine manufacturers names in that spot. Yes, the boatbuilder set the alignment at their factory.

One would think that it would be good and you could trust them.....

Now having said that, How many new cars have you seen that were "perfect" from the factory but were in the shop within a week of delivery?

It's probably still a good idea to check it every year or so (I check mine every other year. (and I installed my engine, gimbal and drive...)

If the drive is off for any reason, I always check it. it takes minutes.....

TilliamWe · Jul 25, 2009

Re: Bravo III is slipping as engine RPMs increase.

HT32BSX115 said:
Now having said that, How many new cars have you seen that were "perfect" from the factory but were in the shop within a week of delivery?
.....

1 out of 11 And it was for a power door lock switch that was not connected.

Checking alignment is a good idea, but just cause a dealer of a brand new boat doesn't do it, doesn't mean they caused the problem. They can catch a problem, but they are not responsible for the problem.

In the original poster's case, the boat is now 6 years old. If the alignment has never been checked, that's not a good thing.

Bravo III is slipping as engine RPMs increase.

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