I/O's

rnbenton

rnbenton

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OK, first I asked about I/O's in salt water, then I asked about Bayliner boats. As expected, I got a lot of valuable information and input.

Now, I want to readdress the I/O subject, mostly as regards to which ones to avoid. Yes, I understand maintenance is a key. But, all things being equal, which ones are good and which ones to be avoided?

Bob
 
Bob: After a few varieies of Merc products, I can say that the BII's are one of the best drives they have. Application-wise, they aren't suitable for a 70mph go fast. But on larger, heavy planing hulls I like the extra mass and the ability to spin the larger props. Help a lot with low speed handling. The other key item, 'specially down here, is there is no impleller in the leg. Runs off a engine mounted raw water pump. Did I mention heavy duty? I whacked a rock pile on the way south and totally trashed the props and a full inspection on the hard showed no evidence of this on the shaft, gearsets, etc. I'd only guess at the damage if it were an Alpha or a BIII.

I'm sure someone will chime in about the Volvo's, but in my opinion, if you look to Merc, BII's are hard to beat.

John
 
The BII does have a good reputation.
Sometime back, someone here ran a poll, Merc vs. Volvo. If I recall, Volvo won about 2 to 1, which was kinda surprising since There are WAY MORE Mercs out there than Volvo. The biggest users of I-O's are SeaRay, Bayliner, Maxum, which all are owned by Brunswick which also owns Merc. I have nothing to back me up on this, but I wouldn't be surprised to learn there are at least 5 Mercs (or more) for every Volvo.
 
Mechanics love Mercs, keeps them in business, if everyone had Volvos there would be a need for fewer mechanics.
 
I had a Yamaha 5.0 with a stern drive and that thing was dang bullet proof. Great motor stern drive combo.

I have Alphas on my searay, and no real issues, just regular maintenance.
 
Volvo is probably the "better drive" and MerC Alpha is probably the "worst drive." From that I mean from a design and buid quality standpoint. MerC had more corrosion problems with B3 than others had with anything. That said I'm gonna tell you the Best I/O:
The Best I/O is the one you can readily get parts and good service on in your area.
 
I can't complain about my '92 Merc Bravo I. The only part it needed was the $5 seal on the steering arm; was getting a slow drip into the bilge.
 
Do the required maintenance and you will not be unhappy with Merc B3s. Cheap out on zincs and maint and you will be very unhappy.
 
Are you buying a new boat, or used? Merc had a problem with the early years bravo 3 (1999 until 2002 or so) that was later corrected with changes to the bearing carrier and number of anodes. I had a 1999 that i tried real hard to keep in tip top shape, but eventually the bearing carrier started to corrode away. i replaced it in 2010 with a new one. It's also important if you have a bravo, or probably any i/o, that your motors idle at spec rpms - if they are idling too fast, your drive won't last long.
 
No experience with Volvo. I've had boats with Merc Bravo III and Alpha I. The BIII is a nice running drive, but I did have to fight corrosion, I had a 2000 year model and after three years of trying about everyting, Mercruiser replaced both drives with the new style, that ended the corrosion problem. I would not hesitate to buy another BIII drive boat, but would probably not keep in in the water. The Alpha I is on a lift kept 18ft runabout - it's a 1999 and other than gearlube and water pump maintenance I have had zero issues with the drive - they are simple, easy to work on and for smaller boats hard to beat. I think a big key here is it is on a lift. I also have heard Bravo II's are just bulletproof drives, probably would be my choice on a larger boat that stays in the water. Bottom line, outdrives have a lot of pluses, but you can't deny there is going to be some additional maintenance - especially if the boat stays in the water.
 
quote:
Originally posted by BillK

after three years of trying about everyting, Mercruiser replaced both drives with the new style, that ended the corrosion problem.
Click to expand...


Bill:

Did Mercruiser replace the drives under warranty? I know that for a long time their response to people with Bravo III corrosion problems was far from exemplary. They denied there was any design problem and blamed all the corrosion on improper maintenance.
 
Rick - Yes, they did replace them under warranty, I didn't pay a dime. A big part was the SeaRay dealer here on Lake Norman was very helpful - it took a year - they tested the docks for stray current first, then replaced the anodes with magnesium, then the mercathode controllers, when non of that stopped the corrosion, they replaced the drives. During that year the old drives continued to run just fine, they just looked really bad. The new drives didn't have a spot of corrosion after 3 years - only maintenance was replacing anodes twice a year.
 
There are a lot of really sad looking BIIs out there running just fine. They are tough. Heavy duty all over, cone clutches (no need for reverse rotation engines), big zincs, wide variety of props, ...
 
We've all read the horror stories on the problems with Volvo's composite drive, so I'd watch out for that one.
I'd say 2000 - 2007 model years or so?
I've got volvo dp's now and have been very happy with them. Also liked the BIII on the last boat tho.
 
My Merc Alphas are relatively easy to maintain and trouble free. The one real drawback to them is the water pump in the drive. I would much rather have the water pump attached to the motor so that the impeller could be changed without taking the boat out of the water and taking the drive apart.
To try to avoid problems I automatically remove the drives when the boat comes out at the end of the season and replace the water pumps before the boat goes back in the next spring.
 
I work with guys who are the local merc/bravo experts. Merc had some difficult years before they added mercathodes and additional zincs. Partly their fault, partly the boat builders not installing bonding system correctly and partly owners using the wrong parts. Merc is extremely poor at communicating why you need to use a certain part or why something was designed a certain way.

To this day, people think they are idiots for having the oil filters upside down when it has to do with having oil where it needs to be when starting the engine.
 
If you think the Mercruiser corrosion problems are gone, you are being mislead. They are still worse than ever in fresh water.
The new Seacore is corroding away now.
 
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