Help needed with drive choice
 

I need some help and opinions on drive choice. You guys seem to be far more qualified than my local Merc guys.

I have a 17000 lb boat with twin Yanmar 6lps (315hp). The boat cruises 600hrs/year at about 26kn with my current Bravo 2s and 17.5 X 21p props.I also have showers from Just Wicked Marine. Overall, I'm happy. The drives have been lasting a while.

My question stems from the fact that I'm slightly underpropped in order to make the drives last, and I'm looking to update my drives at the end of this season. I originally had 23p props and blew several u joints and lowers.

Is there a better drive configuration that would allow me to spin the 23Ps or stainless 21ps? I'd like to extend maintenance intervals as much as possible as well as get maximum efficiency while minimizing breakdowns. At $3/gal, I'd also like to maximize speed.

Also, is Merc still the best drive oil?

I'd appreciate any input as my local guys don't know much at all in comparisson to guys like you who run the hell out of em.
Thanks.

Re: Help needed with drive choice
 

With that heavy of a boat and that many hrs/year, I'd take a serious look at some Konrad drives.

Re: Help needed with drive choice
 

We can help.

www.arneson-industries.com

Re: Help needed with drive choice
 

Konrad Marine has done Hundreds of successful Yanmar installations. We've got many of the Konrad 520/Yanmar 315 packages with well over 4000 hrs!

Feel free to call Fred Sparling at Konrad Marine. He's very intune with the diesel market.

[email protected]
715-386-4203

Re: Help needed with drive choice
 

I was looking to avoid modifications to put a transmission behind the engine. I've looked at Konrad, but I don't really have the room.
The Arneson looks interesting. How expensive of a conversion are we looking? What about speed?
Thanks again for the input.

Re: Help needed with drive choice
 

Arneson

Re: Help needed with drive choice
 

arnison is a good choice but for direct bolt on I would consider bravo 3 x drive you will see about a 20% power and economy increase and should handle the power and weight fine, had a 16,000 dorel with 496s that went through 4 bravo 3s in two years swapped them out to 3x s and has been great since ( owner runs the boat extremely hard......

Re: Help needed with drive choice
 

How about b-maxes?? Might want to call the bravo shop in ft. myers.

Re: Help needed with drive choice
 

I ran a Yanmar 6LP-STZE (300 HP) in front of Bravo III diesel drives for over 6 years and over 2,000 hours. I blew up the first 3 drives within 300 hours each. The current drive has about 1,200 hours on it. I went from a 1.81 ratio to a 2.2 ratio and changed wheels. I also put a drive shower on it. With a very light load, I ran a 28" wheel set and with lighter loads either a 24" or 26" set.

I don't know if it was the newer model drive, the shower or the change in gear ratio, but the latest drive has given me zero problems. I ran mercruiser premium gear lube and changed the oil twice a year when I pull the drive to grease the U joints and lube the drive shaft.

The boat is a 34' center console, single engine, go-fast type hull. It cruised in the mid 30's and tops at 42 under ideal conditions.

Bottom line is that I think a showered diesel drive should do just fine for your engines.

Re: Help needed with drive choice
 

With the Arneson's you will gain speed as well as fuel mileage.

You will have less maintainance and this equates to a happier boater.

We have numerious applicaions with your power or more on boats of similar weight and heavier ones.