98 Mercruiser Bravo III "Stuff"

[HT32BSX115]

98 Mercruiser Bravo III "Stuff"

Howdy all

I have found a 7.4L, B III, eng/sterndrive (100hrs since new) from a boat that was totaled for hull damage. (out of the water presumeably)

Other than asking about closed cooling and whether it was moored in the water Is there anything special about the 98 model year that would be nice to know?



I haven't seen it yet.


Thanks,

Rick

 

[WillyBWright]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Salt water or fresh water would be my biggest concern along with an estimate of total hours. If the boat had an hour meter, get it if you can. A cylinder leakdown test would be worth having, even if you have to pay for it. Then have a look at the oil and gearlube. Also give the rear prop a turn to see if the propshaft has some obvious wobble to it. Look at the anodes, but they're pretty obvious at a glance if they're badly corroded. If they are, look for more corrostion on the drive itself.

I have no specific concerns regarding a 1998 model year beyond the usual wear and tear of a 9 year old unit.

 

[Zackman]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Rick, I'm no B3 expert, but I have one on my boat and have picked up some information about this drive. With the large amount of stainless steel (duo props) and the drive housing being aluminum, corrosion has been an issue with this drive. Some time after 98 (circa 00 - 01), additional anodes where added. One additional (two total) was added to the underside of the anti-cavitation plate and an anode was added to the outer prop nut. The outer prop nut can be added as a retro kit. If corrosion is not an issue, the B3 is a good drive that is very popular.

I believe the MCM will also keep a record of the actual engine hours and is usually more accurate then the typical hour meter, since it will only record hours in which the engine is turning while a remote hour meter usually records hours that the ignition switch is turned on.

 

[QC]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Same comment on the Gimbal ring I made on the Bravo 1. Just make sure it is not wallowed out at the swivel shaft before being installed. Agan not a killer, or a big deal, just needs to be checked before install. If fine, maintaining the proper torque on the U-bolt should keep you from future trouble.

 

[HT32BSX115]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Ok,

I have a little more info on this sterndrive....It does have about 100 hrs on it. A tree fell on it! (the boat) I suspected that. We had up to 90mph winds here in the last few weeks.... I'm sure the insurance co totaled the boat. The owner claims it has been moored in his back yard all these years and was towed to the lake when used. Claims fresh water use only. Asking $6000. It sounds like this will be a good replacement for my King Cobra. It's at a dealer right now and I may ask the dealer to do a comp check and check the drive oil....Although I may just drain a little myself and look myself.

I didn't really want a B III (I wanted a BII) Ant I do want an EFI engine. (Would this be an EFI engine?)

It looks like this 'll be at least similar in performance to my 340hp King.

 

[QC]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

What's the power rating? I believe The 7.4 Model designation was a 330 bhp at the prop and the 454 Mag was a 385? Both were MPI. Get the S/N.

 

[QC]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Also, some side benefits of the B3 are no list due to prop torque, better control when backing as it performs equally well to port or starboard and better hole shot.

 

[HT32BSX115]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

Thanks,


I'll get the SN's and i'll probably take my comp gage and a plug wrench with me.

He didn't say what the power rating was but I'm pretty sure my King Kobra (1987) was rated at crankshaft HP (anyone else know for sure?)

The Mercruiser is rated at propshaft HP if I'm not mistaken.

That would mean that I'll get at least the same performance?

I meant to say earlier that I really wanted a Bravo 1. I know the B3 is a good drive. I am under the impression that the B3 won't be as "fast" as the B1. This boat will GPS at 61MPH with the 340hp King Cobra.

At this point it doesn't really matter....I'm sure the B3 will push it to at least 55 with the right props etc.....(What's 5 mph anyway?)



What year did Mercruiser go to EFI? (97/98 are EFI?)

 

[QC]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

I am not sure about the year, but I am guessing flywheel rated for the King Cobra. Yes EFI, all MPI (multi-point injected) are EFI, not all EFI are MPI . . . I am guessing 1 - 2 MPH better for Bravo 1 vs. 3 although I don't recall ever seeing a back to back test, same boat and that is the only data I would trust. IMHO, outside the galvanic stuff noted above, the biggest drawback to B3 is propeller cost . . .

 

[HT32BSX115]

98 Mercruiser Bravo III stuff

98 Mercruiser Bravo III stuff

Well,

More info..... The engine is raw water cooled. As I said before he claims it was never left in the water and not run in salt at all. He claims to have complete service manuals too.

It's carbureted too.



Just got info on winterization. He said he did it(drained) every year and put a small heater in the boat when covered in the wintertime.


If it REALLY does have 100 (fresh water)hrs on it could I still install a (1/2 sys) closed cooling and have it work ok?


Being a 98 will the dealer be able to scan the engine history and determine actual hrs overheat info etc?

(Probably not since it's carbed)



I only have about 1/2" clearance from the the front of my 460 to the floor in my Four Winns..... I can cut about 1/2" more out of the floor. I'll be measuring carefully to ensure I have clearance. Does anyone know if the OMC 460/King is shorter or longer than a BBC/Bravo?

 

[HT32BSX115]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Well I still haven't been able to go up and look at this setup.

Can someone tell me what exactly I'll have to do to the transom to make the Bravo fit in the OMC King Cobra hole?

I thought I would need some sort of adapter or do some fiberglass work. One guy has told me that the Bravo transom is close to the OMC transom.

What is the REAL answer? (I have not obtained a Bravo template yet)


Thanks,

Rick

 

[HT32BSX115]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Ok,

Well I bought it.

I did a compression check on the engine cold. 140-150psi all cyls. (not bad I guess.....only 128hrs on the engine from 1998 until now)

I guess that's ok on a cold engine with a small battery.

Everything else looked ok.


I did have a panic attack though once I got it on the hoist .......

There was a "freeze" plug popped out on each side!

I put rubber plugs in the holes, disconnected the manifolds, plugged up all the hoses and pressured it up and everything held pressure. It appears that when it was drained the last time a little bit of sand/rust in the bottom of the block (which I could feel around the drain holes) had prevented all the water from draining out and left a little in the bottom of the water jackets which pushed out the soft-plugs.

I believe I have dodged that bullet.


I got everything except the steering wheel for $5K The B3 lower unit has no corrosion, the zincs are nearly corrosion free and the 24p props don't look like they've hit anything solid ....ever

It also has the Mercathode system on it (when did that come out?) I 'm not excited with that system since I'll never leave it in the water for more than a week or so and I'll probably never run it in salt. But I'll make sure it's hooked up and works.



I am a little confused though. I took my tape measure and did a little comparing to the OMC King Cobra.

The distance from the crankshaft centerline to the prop centerline is identical to the B3. The bolt pattern on the King Cobra transom appears to be IDENTICAL to the Bravo transom.

I thought I'd need some sort of adapter plate or need to do some fiber glass work to install the Bravo transom. It looks like even the bolt holes will match up. Am I missing something?


Anyway I guess I'll have a King Cobra transom and 1.43:1 drive (with only about 200hrs on it) for sale. Anyone know what this "stuff" is worth? (to someone that wants it of course!!!)


Cheers,


Rick

 

[Reel Poor]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

I'm not positive about this but I believe the only thing that needs to be done to install the Bravo transom plate is, at the top of the cut-out where the steering arm goes thru the transom. It needs to be trimmed some to allow the Bravo to achieve it's full turning radius.

 

[QC]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Cool deal. I bet she's just as fast as long as the propset is correct. If and when they are right, I bet same speed and maybe more. Awesome!! Keep us informed.

 

[HT32BSX115]

Re: Things to know about a 98 Mercruiser Bravo III

Re: Things to know about a 98 Mercruiser Bravo III

I'm still not sure about the power rating.....

I took the following from the engine.

K 4-74BF10KS (The "K" at the beginning is of a MUCH larger FONT size)

This is the serial number on the side of the engine: 0K276863

What's the power rating? I believe The 7.4 Model designation was a 330 bhp at the prop and the 454 Mag was a 385? Both were MPI. Get the S/N.

 

[QC]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Yeah, I knew this was still unanswered, but I assumed somebody would chime in . . . I have searched and searched and basically got to here. What does the decal say on the intake plenum? 7.4L MPI or 454 MAG. The serial number appears to be actually a 1997 engine, but I don't have the resources a dealer does. These were 330 and 385 bhp respectively at the propshaft.

 

[HT32BSX115]

Re: 98 Mercruiser Bravo III.....well I guess it's a 97

Re: 98 Mercruiser Bravo III.....well I guess it's a 97

Well the boat was a 1998 model but I think the previous owner said the engine/drive was a 1997 model year. It's not an MPI though since it has a carb on it.
(MPI means Multi-port injected?)

I think I may have figured out what this thing is...

7.4L Bravo (Gen. VI) F800700-K999999 Which would be 1996-1997 I guess.

 

[Don S]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Well, haven't looked at this thread since you first started it, but here is some info on it.
It was originally in a 23' Bayliner with hull number BL3A01BCE798 and was sold to the original owner in 98 by Olympic Boat Center in Kirkland WA. VERY close to salt water.............
The Mercriser serial numbers are the numbers you want to use, that K 4-74BF10KS is some kind of OTHER model number Mercriser uses other than how it's listed on the engine. Couldn't even tell you why they do that.
Anyway. Here are the numbers for the engine, transom shield and drive that should all match.

ENG: 0K276863 474BF10KS MERCRUISER 7.4L BRAVO
DRV: 0K186414 5D30181KT MERCRUISER BRAVO 3 1.81:1
TRN: 0L200713 6211001LS MERCRUISER BRAVO TRANSOM

The manufacture date for the engine is 05/01/1997

 

[QC]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

No carbs 1998 and up . . . The 7.4L is 310 bhp @ propshaft then I think. The MPI is a 7.4LX . . . I still think it'll run with your 340 rated at the flywheel. Good luck with everything.

 

[HT32BSX115]

Re: 98 Mercruiser Bravo III

Re: 98 Mercruiser Bravo III

Thanks for the info Don,


Yes VERY close to salt ....He swore up and down that he never put it in salt.. The boat looks it too. He was VERY into wake boarding on Lake Washington.....year round....Talked about getting out of the water and using the heater to warm up in the wintertime! (One of those raw water cabin heaters.....got that too in the deal)

I have the manifolds, risers and extensions off now. It doesn't appear that the manifolds have ever been off. The paint on the studs appeared undisturbed. There's little or no rust in the risers and extensions There *some* rust in the bottom of the exhaust manifold ports. and it appears that there might have been some water that came up thru the shutters in the left side at one time or other. (half of the port shutter is gone)

As I said earlier the zincs look original and there's little or no corrosion. He kept it at the house until the tree fell on it.
If I hadn't seen the boat (and the hr meter), I wouldn't have believed that it only had 128hrs on it.

Anyway it looks like it will be a good fit for my Four Winns.
I am hoping that it runs at least as good as the King Cobra.


I'll post my progress as I put it together. I'm not doing much right now. It's a little cold in my Hanger to do much work. I don't have insulation yet. Once I get it insulated and sheet rocked I'll get my 100,000 BTU furnace going in there and My wife will probably dis-own me!


Cheers,

Rick

Well, haven't looked at this thread since you first started it, but here is some info on it.
It was originally in a 23' Bayliner with hull number BL3A01BCE798 and was sold to the original owner in 98 by Olympic Boat Center in Kirkland WA. VERY close to salt water.............
The Mercriser serial numbers are the numbers you want to use, that K 4-74BF10KS is some kind of OTHER model number Mercriser uses other than how it's listed on the engine. Couldn't even tell you why they do that.
Anyway. Here are the numbers for the engine, transom shield and drive that should all match.

ENG: 0K276863 474BF10KS MERCRUISER 7.4L BRAVO
DRV: 0K186414 5D30181KT MERCRUISER BRAVO 3 1.81:1
TRN: 0L200713 6211001LS MERCRUISER BRAVO TRANSOM

The manufacture date for the engine is 05/01/1997