Pump problems, Drain pumps and Intake pump

[wiker5]

I just finished a ballast overhaul on my 01 Mobius V, I have two different problems.

First, my drain pump (aerator style) when my bag is completely full doesn't hold back the water from the bags, even when not surfing and the boat is flat. It blows water out the outlet hole as if they pump were running, could the pump just be tired and old or would they all do this. How can I make sure it doesn't drain, the easy solution is to add a ball valve, but then I have to open and close it, filling and draining.

Second, my intake pump, I mounted it too high and it's not getting water. I added a petcock and now the pump sits above waterline. How are people mounting pumps if they aren't directly to the through hull. I didn't want it just to bounce around so I had to mount it higher where I could control it but now obviously I need to move it.

For today I faked it just using my tsunami pump that fills from the 12V. The boat surfed great until the bag drained about half full and then just ok. I am pretty happy with the winter upgrades.

Thanks for the help and advice.

[wiker5]

Also, the boat has been in the water 3 days and I have already lost a pin that holds a the swim platform down. It shook loose while on the dock, what is everyone using to make sure this doesn't happen. Bolts with locking nuts? I was lucky I noticed it when I did before we went out.

[gregski]

I'd guess that when your bag is full, the water level (top of the bag) is above the drain outlet. If so, it will drain down to that level. Just physics. For filling: the aerator pumps are not self-priming, so if the pump is above the water, it cannot clear any air in the line to get the water moving. A scupper thru-hull may provide enough pressure while moving to push the water/air up, but that's not really an option for you now. I know there are a few other tricks for getting them primed, I'll let other chime in.

Our platform bracket pins shook loose too (the spring-cam style thing). Just go to Ace and get a stainless clevis pin/cotter pin. If it makes you feel any better, the swim platform floats, so the risk is much lower than you might think

[MLA]

First, my drain pump (aerator style) when my bag is completely full doesn't hold back the water from the bags,

Sorry, but this is how aerator pumps work. Going to have to get the outlet higher then the level of the filled sac.

Second, my intake pump, I mounted it too high and it's not getting water. I added a petcock and now the pump sits above waterline.

Pump has to be below water line. Need a 90 between the thru-hull intake and pump inlet

[kaneboats]

This stuff can be tricky. You may have to throw a 90 degree fitting just above (or below) your shut off valve to keep it low enough. My aerators on some of my fill lines are sitting horizontal. If so, you have to keep the outlet side high so they don't lose prime. Also, you have to loop your drain lines very high, above the tops of the bags so they don't just drain. I cross mine to the opposite side going high behind the back seat rest so they don't accidentally drain. I also use check valves on my fill lines (2 to each rear bag) so they don't drain back toward that pumps. PM me if you want more detail and I'll give you my cell #. Good luck.

[aerolland]

It sounds like you have removed the manifold in favor of a pump per bag, if so this might not help or be cost prohibitive. Otherwise, if you are draining back through your fill lines you could add these 12V servo ball valves:



I replaced my sprinkler manifold with these 1" ball valves and have had nothing but great things to say. It keeps the install simple with 1 pump for the whole boat, although as you can see I left another port for a 2nd pump if I wanted - may do that to double my volume but with 15-ish mins to fill 2600 lbs of water, I'm happy - it takes us that long for the boat to warm up and get to our riding spot from the ramp anyways.


Otherwise you'll have to do the suggestions above - drain loops above the bag, re-positioning your pump(s) below waterline, etc. Good luck!

[MLA]

It sounds like you have removed the manifold in favor of a pump per bag . Otherwise, if you are draining back through your fill lines

Simple check valve is all thats needed.

If one retained the single common pump/manifold, then you do need an electro-mechanical to control both fill distribution to the selected sac(s) and passive draining.

[wiker5]

Thanks for the advice, I went out tonight a plugged the drain hole with an 82 cent cork, it's not a long term fix but my bags stayed full. I think I will re run the line to get loop to the side and above the bag and then back to the drain. I was using the drain on the transom, maybe I just need to add 2 through hulls halfway up the boat. At least now I know what I am up against and know how to fix it. For the intake pump, I have a extra Tusnami 800 that is narrower and will mount to the petcock and will still sit below waterline. I'll install that tomorrow should be an easy fix, and then I'm sure i'll have new problems. I will have to add check valves to the intake lines that makes sense.