View Full Version : Ballast

07-03-2008, 02:07 PM
I have a 07 LSV with the center ballast bag and am deciding now if I should add ballast in the bag. Does anyone know how much the bag in the center weighs when full and how much the gravity 3 ballast system weighs. I'm looking at the fat sacs for the back, 400-440lbs on either side of the engine. Anyone have this set up or any advice?


07-03-2008, 03:06 PM
I have the gravity 3 system and it's 400lb for each bag.

Eric Z
07-03-2008, 05:26 PM
I have 400lb under the front seats, 400lb Mid, 400lb in v-drive with 2 45lb plates under them. Wake is great. I actualy drained some of my fron today and it looked better than ever. So it is more like a 300, 400, 900lb split front to back.

07-03-2008, 08:29 PM
Does anyone know how much the stock bag weighs in the middle ski compartment on the 07 LSV?

07-03-2008, 08:46 PM
07 lsv center ski locker should be 400lbs..... That is if you can fill it all the way up. Usually raises the cover for the ski locker so figure a little under that.

07-03-2008, 10:15 PM
I have 06 LSV.. 07' Grav III has 400lb bags in all three spots.
Do you plan to surf any? if you do, then get the Fly High ProX 750 lb bags.. they fit perfect, still allow room for lifejackets and light stuff..
I never fill the 750s for Wakeboarding, but fill one side for surfing! You'll want the extra weight to get a good surf wave...
If you don't surf, get the fly high 400lbs.. they'll be easy to integrate into your system..

The '06 and newer LSV hull likes weight forward for wakeboarding.. if I fill the rear sacs full and only have 4oo in locker, it does not ride well! PORPOISES!

hope this helps.

07-04-2008, 08:59 AM
No surfing, only wakeboarding. It looks like the 400's are the way to go in the back, but what about the bouncing. Is it real bad or how do you handle it? Does there need to be weight in the front to help it out like another few hundred pounds under the bow seats?

07-04-2008, 02:41 PM
Don't knock surfing until you try it. I was very skeptical, but I bought a damaged board off E-Bay just to give my passengers options.

Now everyone that regularly boats with me wants to surf all the time! It's hard to describe how fun it is.

I'm sure we will go back to doing more boarding than surfing when the newness wears off. However, surfing is great, especially when the water is too choppy to wakeboard.

Like 04Outback said, you can get 750s, but not fill them all the way for boarding. They aren't really any more expensive than the 400s.

07-04-2008, 10:18 PM
YOu'll only need additional front weight if you LOAD the rear up with 1500lb ballast..
Running 400 in center and 800 in rear is fine..

07-07-2008, 10:24 AM
Not knocking surfing, just wanting to focus on wakebaording...one day I may switch it up to surfing but really want to push myself at boarding first.

I was looking at the ballast set up on my boat this weekend and was trying to figure out how to plum in the new bags. I was considering keeping the original pump and doing a manifold to all three bags but am kind of worried that they all three won't fill at the same rate therefor leaving the weight uneven or not completely full. Do I need three pumps or just one more for the back bags? And for the draining I was just going to tap into the original drain line of the single center bag but kind of concerned that I may have a problem with water flowing back into the center bag when I drain the backs. No to sure what to do here, dont want to drill a hole in the boat, possible could find a one way gate or something to put in the tube so back flow wouldnt be a problem, if it even would be a problem.

For anyone who has done this or has the 3 bag set up any advice would be appreciated.


07-07-2008, 02:56 PM

See the link below to some pics of the Gravity III manifold.


There is one fill pump and three empty (evac) pumps on the gravity III system. There is a drain fitting (and a hole in the hull above the water line) for each bag. You are right - the three bags do not fill at the same rate so I fill them all full. That's the only way to know for sure that you've got them equal. So buy the right size bag and fill them all full each time you go wakeboarding. Water will come out of the drain fitting so you will know when they are full. I have the same set up as the 2007 LSV - 3 x 400 lb bag - and the wake is sweet f(for my ability) and the boat rides great (no poirposing or bouncing). I don't think that plumbing the rear bags to the front bag evac pump will work too well since the water from the rear bags has to get there by gravity, not to mention how long it will take to empty all three bags.

I had the dealer convert my system from Gravity I to Gravity III at the time of purchase. They charged me the same as if I had ordered this option from the factory - $795 - which I have learned from this forum was a great deal.


07-07-2008, 05:34 PM
Thanks for the help, but by those pictures I'm a little confused. I'm almost positive that manifold is the fill manifold correct? My fill pump is the same as that and goes to the same location above the transmission but what are those three pump looking things? Are they just strainers or what. They look like additional pumps and its confusing me.

Also, when you talk about the drain holes that go through the hull, is that one for every bag or how does that work. I understand there is an individual drain pump for each bag but it seems like a little much to have to drill 2 more holes for each of the back bags. And it doesn't hurt the drain pumps to have water pushed through them when they aren't turned on and the bags are overflowing.

Another question, (sorry for all these just want to know eveything) is there any EASY way to fill each bag individually without drilling anymore holes through the bottom of the boat?



07-07-2008, 06:44 PM
Those pump looking things are solenoids valves. Just like the ones in your sprinkler system. They allow you to fill each bag independently. They're tied to the fill switches on the dash. The pump is activated when any one of the switches is on. Each switch controls one solenoid and allows water to flow to one bag. So, if your bags are different sizes, you can turn off the flow to that bag while still allowing the other bags to fill. Hope that makes sense.

For emptying, you do need a separate hole for each and a pump. I suppose you could tee a couple of lines together somehow and empty out of the same hole. But I bet you'd start draining one bag into another.

You don't need an additional thru hull hole to add the rear bags. You just need to add the solenoids, switches, and plumbing for the rear bags (for filling). And then a pump for each bag, plumbing and holes for draining.

07-07-2008, 07:39 PM

Looks like deeluk answered your questions so hopefully, you now have a better understanding of what is going on.

Regarding your reluctance to drill additional holes for the drain fittings, it's really not a big deal. It's above the water line, and the hull is only about 1/4" thick where you would be drilling. I just replaced my plastic drain fittings with SS ones so I have three of them that you can have - just pay for the shipping.


07-08-2008, 10:53 AM
Awesome, thanks alot guys. Think I've pretty much got the hang of what I need to do now I just have to figure out where to get everything but I've been searching online and I think I have a handle on that too.

One quick question though. I love the idea of having the solenoids to fill each bag individually, but I don't really like the idea of having every compartment open to see when they are full. Is it safe to have them overflow like you were saying, forcing water through the drain pumps each time you fill them up? I would think it would cause a good amount of stress not only on the pumps but the entire system? Would this cause a problem or nothing to worry about?

Thanks again fellas

07-08-2008, 11:50 AM
I don't think it's a problem to overfill the bags and let them start squirting. Happens to me almost every time I go out. I even use it as an indicator that the bags are full. Depending upon what I have in the back compartments, I do sometimes drain the bags down a bit to allow them to close again. Same for the front. The front one will pop the compartment open if you go too far with it. On my boat at least ('04 LSV). I try to finesse that one and stop it before that happens. The rears I usually just let go until they start peeing.

One thing that is good to do periodically is burp your bags. For the front you have to remove it and squeeze all the air out. The rears should have drain caps. If you put the bags in upside down, you can use them to get the air out of the bag. They seem to get some air in them while trailering. If you have too much air in the bags, you won't be able to fill them as much and hence won't get as much weight in them.

07-08-2008, 05:57 PM
Some people including myself have seen stress related issues with the evac pumps when they have received too much pressure. I do not know if it is just my luck, but I have had two of them crack at the base and begin leaking. I added a vent/overflow valve to my fly high sacs. This stopped the overflow pressure issue and gets the air out of the bags everytime automatically. However the only problem I have seen is that the evac pumps like to cavitate, not sure if this problem existed before, but starting the evac pumps while underway seems to solve the issue.

Overflow line on third fly hig fitting with one way valve:

Rough scematic of my setup: