Slight Vibration

[sailing01]

I recently purchased an 2007 21V Launch and am new to the VDrive inboard world as I have owned I/Os for 30+ years. This weekend I was out pulling a boarder and when making a hard right turn I felt a little vibration that actually made me think I struck the bottom. Upon returning to the lift I did a full inspection of the prop and bottom of the boat but couldn't find even the slightest indication of hitting anything. This happened one more time later in the day as well. While running down the lake at various speeds the boat runs very smooth! Just wondering if any of you have any thoughts before I put this in the shop to have them take a look?

[Diggs]

That vibration was probably in the steering wheel right? That is normal when you are weighted. I think I have heard it described as prop cavitation and those air bubbles running over the rudder. I am not sure this explanation is correct, but you will feel it more when you are weighted heavily and probably not at all if you are not weighted... others might know better, but I believe you can change props or rudders to play with it, but I think it is fairly normal....

[sailing01]

That vibration was probably in the steering wheel right? That is normal when you are weighted. I think I have heard it described as prop cavitation and those air bubbles running over the rudder. I am not sure this explanation is correct, but you will feel it more when you are weighted heavily and probably not at all if you are not weighted... others might know better, but I believe you can change props or rudders to play with it, but I think it is fairly normal....

Yes, I was fully loaded with ballast at the time and I just installed a new Acme prop a few weeks ago as the original had some minor rough edges so I thought I would have it reworked for a spare. The water was also a bit choppy at the time so I could easily believe the cavitation as a possibility. Thanks for the feedback and I'll give it a similar test in a couple of weeks without any ballast! Cheers!

[2500HD]

Yep sounds like cavitation to me. My boat experienced the same thing last weekend while surfing under hevy load and chop. The rpms would waver a bit and you could feel a slight vibration and every so often a good spike in rpm's with what could only be described as a shudder. It has only done it under heavy load and chop though.

[CJD]

Cavitation X 3. We were out today with full bags and it happens continuously when doing hard turns spinning around to pick up a boarder. You could go to less pitch on the prop to eliminate it with the bags full, but that would kill your top end...so it's always a compromise.

[Zim]

Cavitation X 3. We were out today with full bags and it happens continuously when doing hard turns spinning around to pick up a boarder. You could go to less pitch on the prop to eliminate it with the bags full, but that would kill your top end...so it's always a compromise.

If you want to save your good water, don't ever "spin around to pick people up". That sends rollers out 180 degrees on the lake and will blow it out nice and quick. Instead, when your rider falls, come off the throttle while still going straight. Once you're off plane and settled, while no longer making a wake, click back into forward and turn the boat sideways. Let any rollers from behind pass you by while you're sideways so you don't take water over the bow, then continue forward at idle and head back to your rider. Takes a little more time, but it saves your water big time. You'll always be throwing your rollers at the shore, so they dissipate rather than sending a power turn roller out over half of the lake. What you're doing now is what tubers do that destroy a lake. Drive like I described above and you'll have good water all day long. This is especially important if you're in fact running full ballast.


https://www.youtube.com/watch?v=ZoSztXXzufk

[Diggs]

Teaching power turners, one at a time........

[garyholl]

If you want to save your good water, don't ever "spin around to pick people up". That sends rollers out 180 degrees on the lake and will blow it out nice and quick. Instead, when your rider falls, come off the throttle while still going straight. Once you're off plane and settled, while no longer making a wake, click back into forward and turn the boat sideways. Let any rollers from behind pass you by while you're sideways so you don't take water over the bow, then continue forward at idle and head back to your rider. Takes a little more time, but it saves your water big time. You'll always be throwing your rollers at the shore, so they dissipate rather than sending a power turn roller out over half of the lake. What you're doing now is what tubers do that destroy a lake. Drive like I described above and you'll have good water all day long. This is especially important if you're in fact running full ballast.


https://www.youtube.com/watch?v=ZoSztXXzufk
X2. And when we tube, we always go to the "second best" water to preserve the butter for surfers and boarders.

[Jetlink]

X2. And when we tube, we always go to the "second best" water to preserve the butter for surfers and boarders.

This PSA brought to you be considerate boaters everywhere. Remember guys, friends don't let friends power turn.

[Zim]

This PSA brought to you be considerate boaters everywhere. Remember guys, friends don't let friends power turn.

And if they do power turn, they get the shovel to their head. :)

[CJD]

If you want to save your good water, don't ever "spin around to pick people up". That sends rollers out 180 degrees on the lake and will blow it out nice and quick. Instead, when your rider falls, come off the throttle while still going straight. Once you're off plane and settled, while no longer making a wake, click back into forward and turn the boat sideways. Let any rollers from behind pass you by while you're sideways so you don't take water over the bow, then continue forward at idle and head back to your rider. Takes a little more time, but it saves your water big time. You'll always be throwing your rollers at the shore, so they dissipate rather than sending a power turn roller out over half of the lake. What you're doing now is what tubers do that destroy a lake. Drive like I described above and you'll have good water all day long. This is especially important if you're in fact running full ballast.


https://www.youtube.com/watch?v=ZoSztXXzufk

Excellent tip, Mike. I've been trying your technique and it definitely works better for a fully weighted boat. And...I still feel the vibration at low speed with the rudder hard over...so not cavitation. I think it's just prop wash against the rudder that causes it.

[Zim]

Excellent tip, Mike. I've been trying your technique and it definitely works better for a fully weighted boat. And...I still feel the vibration at low speed with the rudder hard over...so not cavitation. I think it's just prop wash against the rudder that causes it.

Good deal! Enjoy your glass water! :)

Sent from my Galaxy S3 using Tapatalk.