Where to start???

[torombolo]

Hi all, I had an incident this Sunday, my Monterey 262 (2001) with a Mercruiser 5.7 (157 hrs) and Bravo 3 it was working fine at 3,200 RPM's suddentlly without any noises or previous warning, it still was running at 3,200 but was particularly SLOW like I was going at 1,500, after that the RPM's would not go over 3500. Immedietlly I thruttle down to 1,500 RPM's and went home, temp was fine at 175 f, oil press fine and level also good.

So here my wquestion to the experts here: Where do I start looking for the source of the problem?
I already called the mechanic and he will take a look but want to have an idea my self.

Thanks in dadvance

 

[tpenfield]

Re: Where to start???

Based on what you described, I would look at the props to see if one of them has a 'spun' hub . . .

 

[torombolo]

Re: Where to start???

Thanks T, it makes sence, if that was the case I would need a new prop or is that fixable?

 

[scoflaw]

Re: Where to start???

Doesn't explain why the RPM's won't go over 3500.

 

[HT32BSX115]

Re: Where to start???

Based on what you described, I would look at the props to see if one of them has a 'spun' hub . . .

Not possible with a Bravo III. There's no hub to "spin"

You may have a coupler failing but there's going to be other evidence of that. Look for black rubber 'dust" behind the engine and a possible burning rubber smell.....

If it's not a rubber coupler failure, it could be spline failure (of the coupler)

That won't be all that obvious except when you put it in gear, the engine will turn faster than the prop.

It also will get much worse(quickly) ....so much so that it'll seem like it doesn't go into gear at all.....

 

[torombolo]

Re: Where to start???

That doesn't sound to good..... After talking to the wife she did mention a noise (quickly gone) like when a belt slips.

Well will see how it goes.
Thanks for the coments!

 

[HT32BSX115]

Re: Where to start???

That doesn't sound to good..... After talking to the wife she did mention a noise (quickly gone) like when a belt slips.

Well will see how it goes.
Thanks for the coments!

You can look back there and see if the drive shaft yoke is turning.

Get a flashlight and have someone start the engine (in the water) while you look at the shaft at the back of the engine where it goes into the transom plate.

Then have them put it in either forward or REV. (make sure the boat is tied to the dock)

If the shaft appears to stop when you put it in gear or is not turning at all, you have a failed coupler.

The drive and the engine will need to be removed (in that order) so it can be replaced.

 

[torombolo]

Re: Where to start???

Well, update, there she sits without the Bravo III, coupler should be installed this week, mechanic opened up the Bravo and everything is in great shape, new seals, new boots. Since this is being done, should I look for anything else as maintenenace?

Thanks in advance

 

[cjjjdeck]

Re: Where to start???

Although your Bravo 3 drive is older than mine, this may still apply to yours. I decided to check in my 2011 Mercruiser Owners Manual after reading this thread and see if there was anything listed under the "drive coupler". Under the Maintenance Section there was an interesting note listed regarding this subject. It states: 'If the boat is operated at idle for prolonged periods of time, coupler should be lubricated every 50 hours on Bravo Drives (150 hours for Alpha Drives)". They recommend pumping grease from a hand grease gun until a small amount begins to push through.

Not sure if this situation applies to you, but it might be good to know moving forward to help avoid another coupler replacement.

 

[torombolo]

Re: Where to start???

CJJ thank you very much for that info. It makes a lot of sence since I dont run my boat pass 3,500 RPM or must of the time run at Idle, previous owner use to ride the same way (or so he said)
Update: Coupler has been mounted, mechanic is waiting on the manifold gaskets and 1 of the bellows that was sold the wrong one.
Hopefully test run on Wednesday.

 

[HT32BSX115]

Re: Where to start???

Your replacement coupler will likely have grease ("Zerk") fittings on it so it can be greased from inside the boat. When it's greased, it's suggested that you use "Coupler" grease available from any Mercury dealer.

ALSO, according to Mercury, the drive should be removed yearly and the alignment checked. proper alignment will give you longest coupler life.

Poor alignment will destroy the coupler in short order. (in only a few hours of use in some cases)


Cheers,


Rick

 

[torombolo]

Re: Where to start???

Well the boat is in the water and it worked great. Now my only problem is that I need to buy a water pump replacement (no problem there) and the Mercury-Oil Pressure Switch #87-864252A01 that I can't find locally (that is a problem) I wanted to go boating next weekend.. arrgghhhhhh

 

[torombolo]

Re: Where to start???

Afternoon averyone, I have another newbie question. Can a tight turn damage the engine coupler?

Thanks in advance for the response!

 

[Bondo]

Re: Where to start???

Afternoon averyone, I have another newbie question. Can a tight turn damage the engine coupler?

Thanks in advance for the response!

Nope,.... Generally speakin' it's from Bad alignment, 'n/ or a lack of Grease...

 

[torombolo]

Re: Where to start???

Thank u! just wanted to make sure