I am encountering a vibration around 2200 to 2500 rpm's just before coming on plane. It only last for a couple of seconds and once it starts noising over to go on top the vibration goes away. This is the only time that the vibration is encountered. I am running twin 525's with Bravo 1 XR drives. Anyone have an idea what the problem could be with the vibration? Also, does anyone know whether the couplers are solid or rubber on this drive and engine set up?

When I come up on plane my prop slips a lot right around 2800 rpms and then hooks up. It does feel like a vibration. That may be what you are feeling.

The vibration seems to have just started and was not present in the past.

My guess would be prop cavitation. What type/kind of props do you have ??

Check the drive, could be a bad gear. Had the same problem last weekend, then kaboom!!

could it just be a u-joint under heavy load???

Could be!! Better check it before this happens.....

I am running Hydromotive P-5X 5 blade props. I had a cavitation problem with Bravo 1's prior to installing the Hydromotives but they have not seemed to cavitate. I did beach the boat and kicked up some mud when I backed off. Could prop damage that you could not see cause cavitation?

not sure about cavitation (sounds possible) but it would cause a vibration

try posting new thread in the prop section

YES, you can very easily bend a blade or two with fine mud!! I have done that!
With my old boat, I beached at a friends house and when I left, I didn't push it out far enough and when I put it in gear, it was still in the muck a little. When I went to get on plane, it was vibrating, not real bad, but it was definitely noticeable. You could feel it in your feet. It would vibrate at certain rpms and not as much at others.
I had the prop checked, and two blades were bent. The polish still looked perfect.

I would have your props checked, =especially= if they were labbed.
Kent