Bravo 3x vs Bravo 2x

[Will Fish]

Posting this for a friend:

A buddy of mine has a 25' Parker powered by a Yanmar 6by 260hp diesel. He has a Bravo 3x diesel drive with a 2.00 ratio. The gears in the drive are shot, but the housing is in good shape. Looking for different options on the drive as these drives are known for failure around 300-350 hours (he had 280hrs on the drive). I think he can run a Bravo 2x with the same transom assembly, but unsure what gear ratio or size prop he should run, as the 3x had dual props. Any info would be helpful.

I was able to find a Bravo 2x for him at a good price in the 1.81 ratio.

 

[haulnazz15]

Re: Bravo 3x vs Bravo 2x

I don't think you'd want to step down to a Bravo 2X from the Bravo 3X simply due to the counter-rotating props. I was under the impression that the 315HP+ Yanmars were the ones who had problems early on with the Bravo 3X's, but that the lower HP Yanmar's were fine. Personally, I'd go back to the 3X again. Does he boat in rough water conditions (i.e. getting air, etc)? If so, that is likely where the drives are being damaged as the peak torque from the engine is being transferred abruptly to the drive when the prop leaves/re-enters the water. I wouldn't think that a 25' boat would pose much of a weight issue, as they use those drives on much larger boats (36'+) with similar results.

 

[Will Fish]

Re: Bravo 3x vs Bravo 2x

I don't think you'd want to step down to a Bravo 2X from the Bravo 3X simply due to the counter-rotating props. I was under the impression that the 315HP+ Yanmars were the ones who had problems early on with the Bravo 3X's, but that the lower HP Yanmar's were fine. Personally, I'd go back to the 3X again. Does he boat in rough water conditions (i.e. getting air, etc)? If so, that is likely where the drives are being damaged as the peak torque from the engine is being transferred abruptly to the drive when the prop leaves/re-enters the water. I wouldn't think that a 25' boat would pose much of a weight issue, as they use those drives on much larger boats (36'+) with similar results.

I do not know the weight of the boat, but it is definately a tank. I've had her offshore with 5-6' rollers with a 2-3' chop. She eats waves for breakfast. I think the main reason is the 6BY Yanmar is about 900lbs alone. There is a big difference on the diesel i/o compared to the single ob.

The boat is never pushed hard and never comes gets air, so I do not think that is the issue. It's main and primary use is inshore fishing in LI sound, with 1-2' chop.

He's still looking for options, but right now is leaning towards rebuilding the same drive.

I forgot to mention it's a Turbo Diesel.

 

[Will Fish]

Re: Bravo 3x vs Bravo 2x

So I'm bringing this thread back to life instead of starting a new one.

Since last post, he brought the drive to a local reputable mercruiser guy to rebuild. After tearing the drive apart he says the drive is not the X drive and is the regular bravo 3. Hence, the problem why the drive never lasted. He mentioned the upper portion (I heard the story from the owner of the boat and not from the mechanic) was made out of aluminum and not the stronger metal (like I said I did not speak to the mechanic).

Now the decision: 1) rebuild the same drive; or 2) buy a brand new X drive which is what should be mated to the Yanmar Turbo Diesel?

Also, can the X gears be installed in the Bravo 3 housing? Any difference in the different drives?

If he decides to buy the X drive (which is most likely the route he will take), should his gear ratio change?

 

[TilliamWe]

Re: Bravo 3x vs Bravo 2x

DonS will know, but I "thought" all the housings were the same. The difference is in the gears/internals.