bubba

ST 31,

Tahnks for asking,what did the mean with this i copy that from Aipacker his reply early in this forum, i would like to know what the loss of trim control is, and what the try to say with the loss of migrange, and last the wicked docking speed those three things

this is a copy from airpacker his reply then,

the loss of trim control, the loss of migrange cruise speed and the wicked docking speedge cruise speed

Again thanks for asking, i really would like to have the info i am ready to buy one if i know enough of the drive.

Best regards sake

Airpacker

Bubba, loss of trim control: because the drive is 5 inches shorter than a Bravo drive, it looses the ability to lift the bow of the boat because it has no leverage against the hull.

Although I gained almost 8 mph top end speed, I lost 10 mph at 4000 rpm because I cannot trim the boat up (see above)

It idles at 8 mph and really jumps forward when shifted so docking can be very interesting, especially in tight quarters.

Cord

iTrader: (2)

I don't think this would be the best drive for a baja. Your current bravo drive would be mine choice. If anything, I'd look for a shortened lower unit and hope that you can get on plane with a Hydromotive prop.

blackhawk

7 mph at 900 rpm isn't too bad. Mine idles at 600 and trimmed in idles about 6 mph. I usually trim it up a bit and lower the tabs all the way down to bring in just under 5 but still has a wake. Frustrating in long no wake zones with 20 or 30 boats ahead of you!

My blackhawk doesn't bang in but youe definitely know when it's in gear. I wouldn't call it smooth. Like Airpacker said 2 31 pitch props underwater puts a big load on everything. I've never tried trimming it up because I know that's hard on u-joints if you go too far. Maybe I'll try it trimmed up a little and see what happens. I also bypassed my safety switch so I start it in gear often.

The "coast method" of docking is best. It can be a real b**ch in crowded areas and fast currents though!

Back to the original question. Like stated here already, the boat must have natural bow lift characteristics. If it doesn't the drive won't work. This is why a lot of cats responded very well to them. So I wouldn't think your boat would work well. Like Cord said a shortie would probably work better.

cobra marty

How about the conversion where the prop shaft is change out to one that is machined for a single #6 prop. Bigger diameter single prop with the BH short profile.

bubba

Thanks for all the info guys, is the bravo 3 also jumping forward whit docking?

HeavyChevSS

Something that might work for you guys that have problems with idle speeds is adding a transmission. When the Blackhawk was new Hot Boat did a test on one with a 31' (or about) V-hull think a Sunsation?? with twin 454's and B & M 2 spd trannys, they were able to use smaller props. Helped idle speed, planing time, and still ran good on top end will dig up the old issue if you can't find it. Think the B&M's are disco'd also along with having to move motors forward a foot to fit them but seemed like set up worked pretty well!
Rick

HeavyChevSS

Isn't Bravo 3 Mercs' version of the Volvo duo-prop, if so should be awesome low end and docking..

Cord

iTrader: (2)

Merc actually created the blackmax transmission for this purpose. 1:1 high and a lower gear for off plane work.

The bravo 3 won't have any of the issue that we are refering too. Simular components, but a totally different setup.

Cobra-I know of the conversion that you are reffering to...I'm not sure. It would be an interesting experiment, but it won't be happening with my drive.

bubba

Thanks again for all the help, do you guys know a used (bh) one for sale