Occasionally though they’ve asked us for instructions, which for the better part of a year has consisted of a brief outline of the process that we forward in an email.  Due to a request on the Moomba boats forum we finally got around to taking some pictures of the process, and figured we would post them here along with a description of the process for everyone to see.

Once you remove your factory fittings head over to our wakeboard fittings category to pick up some replacements for use with a Tsunami pump, or any other application you have.

Lay the bag out on a hard, flat surface (a cement garage floor works well) with the fitting of interest sticking straight up into the air.

Using a hair dryer (and only a hair dryer, nothing more powerful) on it’s low setting, apply heat to the area where the black flange in the bag meets the grey fitting. Leave the hair dryer in place for AT LEAST five minutes.

With the hair dryer still pointed at the bag, stand with your feet on either side of the fitting so the soles of your shoes are on the black flange portion of the bag. The hair dryer should be between your heels pointing at the fitting in the direction you are facing.

With the hair dryer still pointed at the bag, push the end of the fitting straight away from you. Try to get the end of the fitting to touch the ground while your feet hold the flange of the bag flush with the ground.

You will be “popping” the fitting out of the bag, NOT unthreading it. If it doesn’t pop out the first time that’s fine, just start over with step two above. It usually takes a couple of tries to get the process down, but once you do it one time, the rest of the fittings will come out easily.

Once the fitting has been removed both it and the port on the bag are undamaged and ready for reuse.

This process will allow you to use any of the standard Fly High ballast fittings with the ballast bags that came in your boat with fittings cemented in from the factory.

CAUTION: It is very easy to damage the bags beyond repair while trying to remove fittings either by applying too much force or too much heat. Start slowly, and if the fitting does not come out easily repeat from step 2 above.

If you are concerned about damaging your bags, or unwilling to attempt this process you can send your bags to us and we will remove them for a small fee, contact us for more information or to setup that process.

What’s Wrong?
There are three main issues with the factory Gravity III system Supra and Moomba installed from 2002-2008 (the ballast system was essentially identical throughout this entire process, with the exception of bag sizes, which vary by model and the day of manufacture):

1) Slow Fill Times: This is a result of the fact that the factory system uses a single Rule aerator type pump to fill from one to three bags depending on how many switches you turn on at one. Additionally, the system uses solenoid valves designed for use in a below ground irrigation system to control the flow of water to each of the three bags. That means when you turn on the fill switch for a particular bag the system is engaging the fill pump AND opening the solenoid valve to that bag. The more bags you try to fill, the more the longer it’s going to take as the output of the single fill pump is routed to all three bags by the solenoid valves.

Additionally, the sprinkler valves are designed to maintain pressure (which is important for an irrigation system with retractable heads), but decreases volume significantly (which is what we’re interested in for a ballast system). Removing the sprinkler valves would increase the speed of the system by close to 50%, but would sacrifice the ability to control which bag is filling because any time the fill pump is on it would be sending water to all three bags.

2) Inconsistent Draining:  The factory system has an individual Rule drain pump for each bag.  Because aerator pumps are not self-priming it is crucial that the drain pump be mounted in close proximity to the bag it is draining (we prefer to have the pump mounted directly to the bag).  The Gravity III system has the pumps for the rear bags mounted approximately two feet away, which was down to preserve the appearance of the installation.  While it certainly is nice

3) No Vent Connection:  In the factory configuration there are only two connections to each ballast bag; one for filling and one for draining.  While the drain connection can act as an overflow to prevent damage to the bag or boat if the fill pump is left on too long (a common occurrence due to the slow speed of the system), because it is connected to the bottom of the bag it does not allow air in the system to be vented.  That means the bag can have a significant amount of air trapped inside of it, which will limit the capacity of the bag.  This is especially a problem for the center bag, but can occur with all three.

What’s The Fix?
Although the specifics can vary depending on goals, budget and time, there are basically two methods of upgrading the factory system to correct the issues outlined above:

Option 1: Upgrade to reversible flexible vane impeller pumps (Jabsco Ballast Puppy or Johnson Ultra Ballast) which is the route Moomba and Supra have chosen for 2009 and newer boats.  The advantage to this layout is a drastically simplified system with far fewer components, less hose, and a dedicated vent on the top of the factory bag.  Additionally, with one pump connected directly to each bag in the system, fill and drain times are reduced significantly.  The disadvantages to this layout are that it requires the installation of two new thru-hull connections for the additional pumps, and flexible vane impeller pumps are significantly more expensive, so the complete system ends up costing around $900.

Option 2: Install additional aerator type pumps (like Attwood’s Tsunami 800) along with additional hardware resulting in an individual fill pump for each of the bags in the system.  This setup also provides an individual fill and drain pump for all three bags, and does not require the sprinkler valve distribution manifold that is present in the factory system which further increases speed.

This configuration does not allow for a dedicated vent connection off the top of the bag, which is the only real disadvantage.  It’s also significantly cheaper to install this system than the flexible vane impeller based option above, but there is more install work to be done.  The parts for this upgrade total around $300 without the vent connections, or $400 with the hardware to connect a vent line to each bag (which requires bags with three ports on them).

You can view one of our customer’s installation summary on the Supra Boat owners website here.

Other Options
If you are content with the speed of the system and just want to enlarge the capacity of the bags for surfing or wakeboarding we do offer a factory upgrade kit for 2002-2008 Moomba and Supra wakeboard boats which includes everything necessary to replace the rear ballast bag with a larger capacity model (up to 1,450 pounds).

If you have any specific questions about upgrading the ballast system in your Supra or Moomba, feel free to contact us via email at sales@wakemakers.com or by phone at (888) 338-6085.

Moomba uses one Rule 2000GPH pump to fill all of the bags in the boat. If you only have the center ballast option, then it will fill it fairly quickly, but if you’re complaining about the fill speed, you probably have at least GIII system on your boat (or even larger upgraded bags). If that’s the case the fill capacity will be approximately 660GPH to each bag. In an ideal world, that would result in around 5 minute fill times for the standard 400 pound bags, but ballast systems have lots of less than ideal characteristics. In the factory system, the biggest roadblock is the sprinkler valve manifold system that Moomba uses. Even when open, they have less than half the flow volume of the 3/4″ hose that is used in the boat. Cutting the volume of water in half results in fill times of around 10 minutes, nearly twice the ideal rate.

So what does that mean in terms of actually upgrading the speed of the system? The Rule fill pump used in the system is the largest capacity pump you can really get for this application, so there isn’t a quick fix there. Basically, there are two main options for decreasing the fill time:

1. Replace the stock single fill pump and valve manifold system with three individual fill pumps, one for each bag. In addition to increasing the theoretical fill capacity from 2000GPH to 2400GPH (or higher), the big speed up will be removing the restrictive sprinkler valves.
2. Replace the three restrictive sprinkler valves with quarter-turn solenoid valves. These work the same way, but don’t limit flow at all when open. They are expensive though, at around $60 each.

We typically recommend option 1 because it will cost less, be more efficient, and will be more reliable because three pumps are doing the work of one pump. Unfortunately though, neither one will be a simple install, it will require some reworking of the factory components.

If you have additional questions about upgrading the factory ballast system in your Moomba boat, feel free to contact us and we’ll be happy to help outline your options.