Bravo 3 drive ratios

Oct 14, 2018
57
Boat Info
260 Sundancer 2002, 5Kw Westerbeke Genny,
5.0mpi/new B3 in 2023, Simrad gps plotter/sounder.
Engines
Merc 5.0 MPI, w Bravo III Drive
Here I am siting in the sun on my patio
Having a margarita but
Not on my boat out on the lake..
AGAIN...the outdrive saga has reared its ugly head Again..
Bought a rebuilt upper and lower B3 at 2.20 Ratio, I run 22p 3 blade merc props.
A few summers ago...original drive unit failed and I went with a local re/re on the drive with a one year warranty
That ended last June 2022.
Had put 30hrs on it since then, total hrs 60 since re/re..the upper pinion gear tooth broke and migrated into lower...toast.
I'm now ordering a merc oem complete unit..be 18k in canadian $
Original drive ratio was 2.20
Merc manual says the 5.0efi can work with 1.81 ratio or 2.00 ratio or 2.20
My question is if I changed to a 2.0 ratio using my 22p props will my boat pull a bit better from idle.. and get to plane sooner and be able to hit 4500rpm wot.

she's a dog and with my current setup, with drive tucked all waY in and tabs up, she takes .5km or more to lift her stern and get up on plane at 16knts 3000rpm ..then full plane at 19knts 3300rpm and I can start using trimtabs and trimout drive to cruise
At 3500 rpm 23knts.
Wot is wont exceed 3800rpm and 27knts
She will not hit 4000rpm wot.
She has a westerbeke 5.0kw genny
Which is 380lbs, full water, fuel, 4 adults and gear . Add 2 kids on a tube and she will not get up to plane ever...can 2.00 drive ratio help?
 
Im correcting my errors on previous post.
I actually have 20 pitch 3 blade props..my mechanic confirmed the pitch ..my memory is sharp..but darn short..
 
You said 3800 is your max rpm loaded with people and gear.

How about unloaded? Can you hit higher rpm unloaded?

How long have you owned this boat and has it always been like this?

That 5.0 needs to be in tip top shape to get the loaded 260 going.

Going from a 2.2 to a 2.0 with the same props may only make this worse.
 
Can you drop to 17 pitch. Or maybe the upper and lower were a mismatch
 
The is a prop chart somewhere on the searay website. Take a look and see what is supposed to be on the boat. Iirc they state the drive ratio too.
 
The serial number for my outdrive comes up with a 1.62 ratio there's a sticker that came with my boat and all the paperwork that says it's a 172 ratio 2006 5 l MTI alpha 1 Gen 2
 
Stay with the 2.2's in that BIII. Going to 2.0's will make it worse. You might be able to go to 2.43's.

Couple thoughts on your performance... You really need to have a WOT of at least 4200rpm loaded. Not achieving that means you are putting more strain on that motor than it was designed to handle. Cruising at 3500rpm with a WOT of 3800 is asking to blow a head gasket or burn a hole in a piston. You will be far better off propping it reach at the very least 4200 WOT fully loaded. That means you probably will need close to 3800rpm to stay cleanly on plane, but that is way better for the motor than way you are running now.

I'm a big fan of larger motors in cruisers for the reasons you are struggling with. Most manufacturers including Sea Ray commonly offer engine packages that just aren't enough for even the lightest use.

As far as getting on plane, make sure the celery stick is oriented to give you maximum negative trim. It does not come this way from the factory. Maximizing negative trim will dramatically improve ability to get on plane.
 
Stay with the 2.2's in that BIII. Going to 2.0's will make it worse. You might be able to go to 2.43's.

Couple thoughts on your performance... You really need to have a WOT of at least 4200rpm loaded. Not achieving that means you are putting more strain on that motor than it was designed to handle. Cruising at 3500rpm with a WOT of 3800 is asking to blow a head gasket or burn a hole in a piston. You will be far better off propping it reach at the very least 4200 WOT fully loaded. That means you probably will need close to 3800rpm to stay cleanly on plane, but that is way better for the motor than way you are running now.

I'm a big fan of larger motors in cruisers for the reasons you are struggling with. Most manufacturers including Sea Ray commonly offer engine packages that just aren't enough for even the lightest use.

As far as getting on plane, make sure the celery stick is oriented to give you maximum negative trim. It does not come this way from the factory. Maximizing negative trim will dramatically improve ability to get on plane.
Thank you for all feed back.
I've gone ahead and ordered an OEM Bravo 3 in 2.20 Ratio.
Be about 3 weeks to the shop here.
Mechanic is heading on an Westcoast tuna fishing trip right when eta on drive...lol ..June is shot for an already way to short boating season.
I did install the "celery" stick to give more trim tuck in on drive after my first drive grenade'd and have reinstalled in that fashion since.
I'm definitely considering reproping to 17 - 18 inch pitch props on this new drive.
The 5.0 efi has run well since I bought the boat, cant say anything bad other than I agree on being very under powered at 260 hp for the weight of this model and then add people and gear. I would keep a small block ( bit more room in engine bay) but replace with 383 stroker if she calves. Crossed fingers it dosent, wife is getting concerned on boat bucks flying out of the account..lol.
I've replaced plugs, wires, rotor and cap as well as added a nline water separator on fuel system...
 
I had the exact same boat as you with the exact same HP and gear ratio - although I had 22" props. NOTE that 22" props would make it HARDER to get on plane. Something is wrong - your performance is NOT normal with that setup. I could hit 40MPH (GPS) at about 4,800RPM and could easily pull a skier out of the water or pull tubes. I had zero issues getting on plane - even without using the tabs.

Side note... putting tabs all the way down will tremendously help your hole shot. I say this because it sounds like you are not using them for your hole shot for some reason?
 
Will a 17 pitch give more rpm on the top or less. Sounds like he needs different props with less pitch
 
Will a 17 pitch give more rpm on the top or less. Sounds like he needs different props with less pitch
Yes, a set of lower pitched props would increase hole shot and RPM on the top end. But this would be a band-aid fix (read my post).
 
Yes, a set of lower pitched props would increase hole shot and RPM on the top end. But this would be a band-aid fix (read my post).
Scott - as Lazy states something seems off.
Plus these are dual props so throwing around trying another set is in the thousand dollar range..
 
Thank you for all feed back.
I've gone ahead and ordered an OEM Bravo 3 in 2.20 Ratio.
Be about 3 weeks to the shop here.
Mechanic is heading on an Westcoast tuna fishing trip right when eta on drive...lol ..June is shot for an already way to short boating season.
I did install the "celery" stick to give more trim tuck in on drive after my first drive grenade'd and have reinstalled in that fashion since.
I'm definitely considering reproping to 17 - 18 inch pitch props on this new drive.
The 5.0 efi has run well since I bought the boat, cant say anything bad other than I agree on being very under powered at 260 hp for the weight of this model and then add people and gear. I would keep a small block ( bit more room in engine bay) but replace with 383 stroker if she calves. Crossed fingers it dosent, wife is getting concerned on boat bucks flying out of the account..lol.
I've replaced plugs, wires, rotor and cap as well as added a nline water separator on fuel system...
Lazydaze has an apples to apples comparison for you in post #9.
Before you start dropping $$$ on new props, Do a compression test and fuel pressure test on that motor. This will confirm or rule out a few things as the cause of your troubles. As you stated, you’ve got the time while waiting for the new drive to be delivered.
 
I didn't catch that whole thing rite. Re read and see his max rpm. I have a 5.0 MPI alpha and I know it will go to 4500 rpm or higher I haven't given it all it has yet since I've had it. My cruise rpm is 3300 to 3500 at 27 to 29 mph on gps that's cruising speed. So I see what you mean about the motor not being rite, thanks
 
We launched this past Tuesday.. Yeahhh...17k later
Brand new Bravo 3 drive upper and lower 2.20 ratio shipped up from Texas. My 20 inch pitch 3 blade props up and running c/w merc 3 yr warranty.
I had the mech do fuel pressure test and was within spec he said, also did compression
Test on engine, cylinders 1,2,3,4,7 8
All are 145-155 but cylinders 5,6 are at 90 and 105 .
Speaking with my mechanic and some other master mechanics, they all recommended I run it like normal.
3 outta 4 recomended put a high milage low compression additive into my oil and run it like that for 20 hrs or so. Then do an oil & filter change and do another compression Test to see if any improvements..If compression goes up to 130 or better , run it like I stole it till something changes. Be good for another 500- 1000 hrs.
If compression doesn't improve on problem cylinders
We'll do a wet /dry compression Test to narrow down the issue a bit further.
But since launch day, I accumulated
8 hrs running, maybe an hr at 1000 or less rpm but the rest at 3000 to 4000 rpm...it spins up to 4000 rpm no problem now. I think the reconditioned b3 I bought before was still not right, either geat ratio wasn't 2 .20 or something internal was binding..
The hole shot now is as I remember it when I first bought the boat.
4 big 220lb+ adults and my 10 year old on board yesterday and she climbed onto plane with out an issue, with drive tucked in , planes fully down. Throttled down trimmed out, once up ontop and cruised at 3600-3800
24- 28 mph.gps
Pushed to 4000 rpm and also no issues.
I Trimmed her out and planes partially retracted she hit 31mphgps... I haven't done a light load
WOT run yet, but I do want to see the top rpm and top speed. Fuel should be to 1/2 tank tomorrow when We're out on lake for a day swimming, the lakes at 76deg now, tubing ( finally) and a BBQ
I Will post the results.
Thank you all for your great assistance in this B3 drive saga.
 

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