Axis Wakeboard Boat Forum

Hey guys first time plumbing bangs into my boat. Currently i have 2 750 bags in the back that you manually have to fill with a pump. Getting tired of doing this. The guy before me bought a wake makers kit for one side. I want to install it but have no idea how to. All I have is a bunch of black tubing and some red connectors.

I get that there is one fill line and 2 drains correct?

I watched a video of a guy with a Axis on YouTube plumbing in his bags and it look like he literally just pulls the plugs off existing lines and puts the new connectors on and that's it. Also he has a valve to turn the flow on and off. I don't have any of these existing lines in my boat? I can get pictures tonight of what i have. Not sure if i have pull the flooring up to get to the lines on the stock tank?

I'm in a similar situation- new A20 owner as of last autumn and want to add some bags to the rear lockers.

The fact that you don't see the three existing lines with plugs indicates that your boat did not have the plug and play option installed (also like mine).

I've spent a fair amount of time reading other threads on this topic, both here and over at The Malibu Crew. Based on my research and the bags that came with my boat, I've designed a solution that *should* work for me. I believe that this would be called a variant of the the piggy back installation. Here's what I came up with:


Notes to go along with my diagram:
- There are two anti-siphon loops shown here because that's what already installed in my A20. I may or may not end up using both of them
- One of the check valves going to the vent is crossed out. This is because the hard tank needs to 'breath' both in and out.
- The barbed tee on the drain pump has been replaced by a different solution which Phoenix was so kind to document here: https://www.themalibucrew.com/index.php ... tallation/
I was able to find the parts I needed at my local Lowes for the dual-drain

You'll notice that my diagram has a bunch of part numbers on there. That's because I was using this to create a bill of materials to order from WakeMakers.

I'm going to be installing this setup in a few days. I'll post a follow-up with the results and some photos.

Okay, I'm way overdue to post an update- so here's a brief one-

I started plumbing in the piggyback system as I laid it out in the diagram. In the process I found that the threaded fitting on the port rear tank, which the barbed fitting is attached coming from the fill pump was split down the side and leaking when the tank was full. Having a bag connected to the tank meant if there was water in the bag, it was going to leak all the time. Apparently this is a common failure, which is lucky for me because I was able to find some posts on how others solved the problem. Long story short, removed the hose from the barb fitting, unscrewed the barb from the tank, cleaned and dried the split area on the threaded tank fitting, applied silicone caulk to the threaded portion AND inside the split. I then screwed the barbed fitting all the way in.

Interesting note here: the barbed fitting appeared to screwed all the way in when this boat came from the factory. There was no way the barbed fitting could be screwed in to the point where it bottomed out without causing the female threaded fitting to somehow give. I'm pretty certain that if someone had made one fewer rotations of the barbed fitting, it wouldn't have broken. Anyway, with the fitting bottomed out and the split wide open, I squeezed some more silicone into the crack, then backed the barbed fitting off one rotation allowing the crack to close. Next I put a pipe clamp around the outside of the fitting and snugged it up. It's been a couple weeks, and so far, so good. If it starts to leak again, I'll repeat the process, but try using just a little bit of open flame on the HDPE material around the crack to make it more 'wettable' (mentioned in another post), then try some 3M 5200 marine sealant in place of silicone.

The next part was building the tee connection to go on the drain pump inlet. There wasn't enough room in the space where the drain pump is installed for the tee and other pieces to come straight off the pump inlet. I was able to solve this by improvising a bending jig in my picnic table and taking the heat gun to the tee. Put a slight bend in the tee that roughly matched the angle of the back wall (transom) of locker. With the difficult problems solved, I plumbed the rest in and was ready to test.

The result: Filling seemed to work pretty well. As well as could be expected. I found that the bag was not only filling through the fill line coming from the fill pump, but was also filling via the shared drain connection as well. As far as draining goes, it worked kinda okay as long as there was water filling the drain line from the bag. As the tank became more empty, the drain pump would lose its prime. For testing purposes, I was able to blow some pressure into the drain line after removing it from the bag, then stick my finger in it to maintain pump prime. Not a sustainable process. Additionally, the added length of adapters on the drain pump resulted in the pump residing higher than the drain port on the hard tank. This meant I couldn't drain the tank to same, nearly empty, level which was possible prior to the modification.

All in all, I did not like this set up. I made up my mind to stop messing around with the piggyback set up, and convert to a couple independent reversible pumps with dedicated thru-hull fittings. They'll be quicker, neater, much more reliable.

My advice thus far would be to not attempt the dual-inlet modification of the existing pump in a piggyback set up, at least for a 2012 A20. This was a fun experiment for me, so I didn't mind too much. Could be very frustrating for someone who just wants to plug and play.

I'll come back with some pictures of all this in a bit.

@jyamaharider - How is your project going so far? Are you enjoying your boat or what?!

I found the piggy back system didn't work too well so took the advice of many and took out the fixed ballast and just run with large bags with a fill, vent and drain line - works much better.

Will keep piggyback for centre but use an impeller pump rather an aerator for the center bag because it doesn't need positive gravity feed