Pro 750 project begins

[lib135]

Can someone explain to this thread to me on a very high level, why take out the stock tanks, as opposed to just adding to them? Just to prevent taking up more space? I would like to add additional ballast to the stock tanks. Can someone in a nutshell explain how to plumb, say a 400lb sack into the the prexisting stock tank? or point me to a thread that explains this? Thanks. Can you also explain what a quick disconnect is and what and electrical connect/disconnect is? Thanks

Edited March 9, 2007 by lib135

[Ronnie]

The boats that are being modified in this thread have the tanks above the floor in the lockers. Your's is below the floor and is MUCH easier to install.

These installs have been discussed MANY times on this website. If you will try the search function you can read for hours about it.

[kb3]

The boats that are being modified in this thread have the tanks above the floor in the lockers. Your's is below the floor and is MUCH easier to install.

Ronnie,

I may be missing something here, but I wouldn't qualify the new boats as "much easier to install" The older boats you can just remove the hard tanks and utilize the existing pumps, wiring and hoses. If you are trying to supplement the underfloor tanks on the new boats, it could turn in to quite a bit of work. I am going to be adding 750's to each locker and as far as I can tell I am going to have to add several pumps, all the wiring & switches and new hoses as well as possibly drill through the hull . I know there has been some discussion about putting the sacks in-line with the underfloor tanks, but it doesnt really offer up the flexibility I desire. Please correct me if I am making this harder than it should be.

Ken

[lib135]

The boats that are being modified in this thread have the tanks above the floor in the lockers. Your's is below the floor and is MUCH easier to install.

Ronnie,

I may be missing something here, but I wouldn't qualify the new boats as "much easier to install" The older boats you can just remove the hard tanks and utilize the existing pumps, wiring and hoses. If you are trying to supplement the underfloor tanks on the new boats, it could turn in to quite a bit of work. I am going to be adding 750's to each locker and as far as I can tell I am going to have to add several pumps, all the wiring & switches and new hoses as well as possibly drill through the hull . I know there has been some discussion about putting the sacks in-line with the underfloor tanks, but it doesnt really offer up the flexibility I desire. Please correct me if I am making this harder than it should be.

Ken

Ronnie,

I have heard you can tap into the existing plumbing underneath the floor, so you don't have to run new hoses, wiring or drill. That is what I am trying to get more detail on.

[Ronnie]

The boats that are being modified in this thread have the tanks above the floor in the lockers. Your's is below the floor and is MUCH easier to install.

Ronnie,

I may be missing something here, but I wouldn't qualify the new boats as "much easier to install" The older boats you can just remove the hard tanks and utilize the existing pumps, wiring and hoses. If you are trying to supplement the underfloor tanks on the new boats, it could turn in to quite a bit of work. I am going to be adding 750's to each locker and as far as I can tell I am going to have to add several pumps, all the wiring & switches and new hoses as well as possibly drill through the hull . I know there has been some discussion about putting the sacks in-line with the underfloor tanks, but it doesnt really offer up the flexibility I desire. Please correct me if I am making this harder than it should be.

Ken

Ronnie,

I have heard you can tap into the existing plumbing underneath the floor, so you don't have to run new hoses, wiring or drill. That is what I am trying to get more detail on.

Ken,

Not sure if you are making it harder than it should be or not when you say that type of install doesn't offer up the flexibility you desire. If you are just wanting to install the extra sacs inline with the floor tanks, that is not a hard install. Several of the members have done it with only a few problems. mainly pushing water out the drain lines. This can be remedied with the hose looping up above the sac if it is siphoning out, and it takes a ball valve if it is being pushed out.

eubanks did this type of install and his problem was water pushing out the drain. He never posted on his fix but it would only take a ball valve to close the drain until you needed it. If you are wanting a system where you don't have to get up out of your seat, you will have to use inline electric valves to stop the unwanted drain. If you are wanting a system where your tanks & sacs are separate, you are going to have to install more pumps and drains unless you use a manifold which lets you direct which pumps fills which tank/sac.

cbrown was going to try this install, not sure he ever did.

My suggestion is if you want a different type of install, is to post that question on another new thread. When you are trying to explain installs on different models of boats, it becomes hard to understand the process since both installs are different unless you are familiar with both systems.

lib135,

Basically the install was to take the overflow hose from the floor tank and run it to the above the floor sac. Then take the overflow from the sac to the through hull. This way the floor tank would fill and then the sac would start filling. When the sac was full it would flow out the vent. To drain, the sac would drain into the floor tank as the floor tank was emptying. The sac would put pressure on the tank so it actually pushed water out the drain pump. This is where you would need the valve.

Malibu does have a weight restriction on the floor over the tanks. This install should be at your own risk.

[kb3]

The boats that are being modified in this thread have the tanks above the floor in the lockers. Your's is below the floor and is MUCH easier to install.

Ronnie,

I may be missing something here, but I wouldn't qualify the new boats as "much easier to install" The older boats you can just remove the hard tanks and utilize the existing pumps, wiring and hoses. If you are trying to supplement the underfloor tanks on the new boats, it could turn in to quite a bit of work. I am going to be adding 750's to each locker and as far as I can tell I am going to have to add several pumps, all the wiring & switches and new hoses as well as possibly drill through the hull . I know there has been some discussion about putting the sacks in-line with the underfloor tanks, but it doesnt really offer up the flexibility I desire. Please correct me if I am making this harder than it should be.

Ken

Ronnie,

I have heard you can tap into the existing plumbing underneath the floor, so you don't have to run new hoses, wiring or drill. That is what I am trying to get more detail on.

Ken,

Not sure if you are making it harder than it should be or not when you say that type of install doesn't offer up the flexibility you desire. If you are just wanting to install the extra sacs inline with the floor tanks, that is not a hard install. Several of the members have done it with only a few problems. mainly pushing water out the drain lines. This can be remedied with the hose looping up above the sac if it is siphoning out, and it takes a ball valve if it is being pushed out.

My suggestion is if you want a different type of install, is to post that question on another new thread. When you are trying to explain installs on different models of boats, it becomes hard to understand the process since both installs are different unless you are familiar with both systems.

Ronnie,

I think we are talking the same thing here, I just felt you were offering up only one approach, the simple one. There are plusses and minuses to each type of install, but I wanted to point out there is many methods to accomplish a similar goal. I have mine all figured out, i was just playing the devil's advocate. Thanks for confirming.

Ken

[Ronnie]

I was just referring to the installs in this thread. They only changed the pumps for more volume.

How are you doing your's?

[lib135]

Ronnie,

Can you explain the venting process. I understand flowing the overflow into the sac, and the drain out the hull, but where do I vent? and also, explain where I put the ball valve, and when it should be opened vs. closed. Thanks!

[Ronnie]

Vent=overflow. The air is expelled out the overflow/vent hose from the tank to the sac to the outside of the boat until the tank & sac fills. Then the water flows out the through hull fitting showing you that they are full.

The water flow to fill:

1. Water comes in the fill pump located in the bottom of the boat.

2. Water enters the hard tank (below the floor) until it fills completely.

3. Water then is forced into the sac through the hose that was the overflow hose on the hard tank which now connects to the sac.

4. Water flows through the hard tank and into the sac until the sac fills and flows out the sac overflow hose to the side of the boat. Now both tanks are full. The downward pressure from the full sac over the hard tank is too much for the drain (and sometimes the fill) pumps to hold back. It is on these lines that the water can back flow through the pumps. Here you will have to put in the ball valve (or a valve of some sort) or loop the hose, depending on the situation to stop that back flow, so when they are filling the drain hose valves will be closed & the fill valve if you have one will be open. The valve on the fill line will be closed after the tank/sacs are full. Some of the members are using a check (one way) valve on the fill side.

Water flow on emptying:

1. Water flows out the drain hose from the hard tank drain pump mounted on the tank under the floor.

2. Water from sac back flows into the hard tank below it as the hard tank empties. When you are draining the tanks the ball valves would have to be open.

[kb3]

I was just referring to the installs in this thread. They only changed the pumps for more volume.

How are you doing your's?

I have it all worked out in my head, and with this warm weather we are having, I better get started on it. I want to be able to fill and empty the sacks separately from the hard tanks. If they fill together you will have to be watching the sacks to determine how much water is in them or when the tanks are full. The fully loaded tanks on the 247 put out more wake than I need for boarding, but want sacks for surfing.

I am going to make it as fully automatic as possible, two new switches on the stereo remote plate, check valves on the fill lines, etc. I really don't want to have to open or close any valves manually, so therefore I think I will need four pumps, two fill and two empty. I may try to T the drains and overflows into the existing hoses just before exiting the boat, again with check valves, so that I don't have to put more holes in the side of the boat.

That is my plan until someone shoots holes in it or I install it and it doesn't work.

[Brad B]

No valve between the tank and the sac - the air has to be able to escape when filling the tank and check valve won't work cuz water hasta flow back to the tank.

This pressure has been the quandy of this setup.

But the best solution is loop the hose from the tank to the sac as high as possible.

Also I would think high volume pumps would help insure that the water would be pushe easily from the tank to the sac even when the sac is near full.

I don't have this setup so only postulating

[Ronnie]

I was just referring to the installs in this thread. They only changed the pumps for more volume.

How are you doing your's?

I have it all worked out in my head, and with this warm weather we are having, I better get started on it. I want to be able to fill and empty the sacks separately from the hard tanks. If they fill together you will have to be watching the sacks to determine how much water is in them or when the tanks are full. The fully loaded tanks on the 247 put out more wake than I need for boarding, but want sacks for surfing.

I am going to make it as fully automatic as possible, two new switches on the stereo remote plate, check valves on the fill lines, etc. I really don't want to have to open or close any valves manually, so therefore I think I will need four pumps, two fill and two empty. I may try to T the drains and overflows into the existing hoses just before exiting the boat, again with check valves, so that I don't have to put more holes in the side of the boat.

That is my plan until someone shoots holes in it or I install it and it doesn't work.

If they fill together you can monitor the overflow to tell when they are full. You know it has only been in the last two years that Malibu offered a ballast level gauge. Before that we had to always depend on the overflow to tell when they were full. If you are only partially filling the sacs, you will have to look anyway.

[Brad B]

Instead of the blue waterbed fittings.

This is a piece of 3/4" i.d. braided hose with a female waterhose fitting.

Fits very snug into SL Launch Pads and are much stronger than the blues.

[D-GOOSE]

Tried out my set up this weekend (just like brads) and all I can say is what a wake. I forgot to set it up for surfing but man was that a huge wake for boarding. The one thing I did wrong was not taking my drain hose all the way to the top of the hull. The bag just drained out the side of the boat untell both the bag and drain hole was at the same height.

This is what I was thinking and wanted to know who has done this. Plug the drain plug and just have it over flow out the drain hose. I don't think the pump will hold back the water. I was also thinking and going to try putting a 5 psi check valve at the drain hose to hold a little bit of PSI in the bag. One other thing I have to do (because I have the smaller lockers being a 03 VLX) is put a bar across my eng side cover so it's not pushing it into the eng.

[WakeGirl]

Tried out my set up this weekend (just like brads) and all I can say is what a wake. I forgot to set it up for surfing but man was that a huge wake for boarding. The one thing I did wrong was not taking my drain hose all the way to the top of the hull. The bag just drained out the side of the boat untell both the bag and drain hole was at the same height.

This is what I was thinking and wanted to know who has done this. Plug the drain plug and just have it over flow out the drain hose. I don't think the pump will hold back the water. I was also thinking and going to try putting a 5 psi check valve at the drain hose to hold a little bit of PSI in the bag. One other thing I have to do (because I have the smaller lockers being a 03 VLX) is put a bar across my eng side cover so it's not pushing it into the eng.

I assume that you mean plug the vent line & make the drain line work as the overflow? The only problem with that is that you'll have to manually burp the bag, because it's not a question of air getting in there. Just how much.

[D-GOOSE]

Tried out my set up this weekend (just like brads) and all I can say is what a wake. I forgot to set it up for surfing but man was that a huge wake for boarding. The one thing I did wrong was not taking my drain hose all the way to the top of the hull. The bag just drained out the side of the boat untell both the bag and drain hole was at the same height.

This is what I was thinking and wanted to know who has done this. Plug the drain plug and just have it over flow out the drain hose. I don't think the pump will hold back the water. I was also thinking and going to try putting a 5 psi check valve at the drain hose to hold a little bit of PSI in the bag. One other thing I have to do (because I have the smaller lockers being a 03 VLX) is put a bar across my eng side cover so it's not pushing it into the eng.

I assume that you mean plug the vent line & make the drain line work as the overflow? The only problem with that is that you'll have to manually burp the bag, because it's not a question of air getting in there. Just how much.

Yep your right its the drain line. I was thinking also that if I didn't put in the one way check valve that the air in the top of the bag would be pushed back through the fill tube some. But yes, how much air is the question. I thinking burping would only need to be done when surfing and the bags are filled to capacity.

[WakeGirl]

Yeah, probably so. So basically if you don't mind burping it manually, then I don't see why that would be a problem.

[D-GOOSE]

Will have to see. I already have the drain hose hooked up so all I need to do is just cap it or put in a shut off valve.

[D-GOOSE]

Pics of the wake with a 250lb bag up front, 300 MLS up front, rear 750 bags a little over half full and no wedge.

[Brad B]

I wouldn't put a check valve on the drain.

You need this to flow free but if you take a loop all the way up it won't leak out.

I wrapped around the fuel hose entrance - my thru hulls are in the same vicinity.

I have now done sacs with a vent and without - I definitely like with better.

With a vent the sacs fill more consistently and dont "push" their space.

Also with a vent hose there is less pressure on the drain so the loop is effective.

JMHO YMMV

[lib135]

I am confused on the "loop" can you explain what exactly you are doing?

[srud]

Pics of the wake with a 250lb bag up front, 300 MLS up front, rear 750 bags a little over half full and no wedge.

Whoa! That would be plenty of wake for me!

[WaveMake'nLSV]

Basically, you take the drain line and run it as far up the gunnel side as possible and literally put a LOOP in it. What that does is prevent a siphon from forming and auto-draining whilst underway.

Hope this helps,

I am confused on the "loop" can you explain what exactly you are doing?

[D-GOOSE]

- I definitely like with better.

I have my vent line all the way up under the rail. I did mess up by not staping my drain line up high and agree that putting a check valve on the drain would be bad, but what about on the vent line?

[Brad B]

You can see the 3/4" i.d. hose looping here.

This is the hose that comes from the drain pump.

It goes all the way up and around the fuel hose thru hull connection.

That pretty much makes it touch the top of the gunnel underside.