Really rough vibrations when surfing

[Fastfifty]

Hi Everyone!

This might be in the wrong section but here goes. When the boat is heavily weighted down on one side, especially with someone hanging on tower on one side for surfing, there is a rough vibration, almost like the prop is spinning in the water... my question is, could this be related to possibly a bent prop? or have others had the same problem... could it be something else? the boat actually stops accelerating when this happens and it only happens occasionally, a few seconds at a time... is it actually possible that the prop comes out of the water enough to not be driving the boat forward?

I have an 08 xlv grav games edition with 750 + 540 in back locker and 6 people in boat.

[deafgoose]

The vibrations of a bent prop would simply get even worse as you increase speed so if you are only getting the vibration at surfing speed that is weird.

When I changed my prop from a 13x17 to an OJ 14.25x14 I do get this growl/vibration from 8-12mph. That is caused by the prop but its normal for that prop.

[deepcove]

if it only happens when you are surfing it sounds like prop slippage. I know a guy with a Supra 20SSV that does the same thing when weighted for surfing. You may want to look into a different prop that is designed for all the extra weight.

[you da man]

Get rid of the OJ wakeboard prop and get the Acme 1235 prop...no vibration, better steering, more torque, and cleaner wake. I surf with 1100lb rear surf side sac, 250lbs filled on the opposite rear sac, 1180 center sac, 400lbs of Pop Bags under surf side seat, 400lb sac on top of surf side seat, and 400lb sac on the bow. The weight might be overkill but I have a very long pocket on the goofy side. I don't need the extra 400lb sac on the seats on the regular side but I still shift the Pop Bags under the seat.

[h2oskierrick]

I agree with deepcove, it's most likely cavitation.

[Razzman]

If you have the OJ 14.25x14 wakeboard prop then you are probably easily mistaking the growling noise this prop makes at low speed for a vibration. It is notorius for it and just about everyone who has it comments on it. Call OJ before you go out and spend bucks for a new prop or try to diagnose an issue that doesn't exist as they can correct the issue for a fraction of the cost.

[zegm]

If you have the OJ 14.25x14 wakeboard prop then you are probably easily mistaking the growling noise this prop makes at low speed for a vibration. It is notorius for it and just about everyone who has it comments on it. Call OJ before you go out and spend bucks for a new prop or try to diagnose an issue that doesn't exist as they can correct the issue for a fraction of the cost.

Eric at OJ is great to work with!!! With his recommendation we were able to tone down the wake behind our LS so we could use the slalom course without worrying about going W2W on a slalom ski.

[STANG KILLA SS]

your prop is getting air. cavitating.
it only happens when surfing because of the lean. your basically lifting the prop out of the water by leaning the boat over. the more weight you add, the worse it will get.

[Razzman]

your prop is getting air. cavitating.
it only happens when surfing because of the lean. your basically lifting the prop out of the water by leaning the boat over. the more weight you add, the worse it will get.

I will disagree with that assesment Stang Killa. My 14.25x14 OJ sounds and feels exactly the same whether i'm surfing or not and i run 750 lbs in the locker plus 4-5 large peeps surfside for around and adittional 800+ pounds (seriously). I've had the rubrail in the water with no change, why? Because your not going fast enough to lift the boat enough to cause cav. I have however cavved the prop one time in a different scenario and once you do you'll immediately know the difference and it ain't no vibration i'll say that.

[thesack]

More then likely you are getting cavitation. Without getting into specific details, it has to do with the angle of your boat and prop with the movement of the water and air molelcules in the water. When you cavitate it will have a vibration and noise associated with it.

A different size, pitch, or cup prop would probably fix your cavitation issue while surfing.