Aerator Pump & Fly High FYI

Well, it's been a few months now with my ~2,200 lb automated ballast system on my '00 MC 230 VRS and I've had to go through a couple of minor revisions due to a few small details that I never picked up in the various writeups I read.

1) Fly High's bags are not a "true" 3/4" NPS thread. The female threads in the bags themselves may technically be but, apparently due to the softness of the material, it appears that they oversize their male fittings to account for the stretch in the female fittings. This is not worth mentioning if you're using all Fly High fittings into the bags but I wouldn't recommend planning on screwing a real 3/4" NPS male into a bag unless it's a really low stress situation (Maybe in a bow sac).

I started with the T800 pumps screwed straight into the rear bags. This seemed ok at first although I couldn't screw them in very tight at all. I'd get them tight and then the female threads would stretch out and jump to the next loosest thread. I let it ride this way and one of my 750s pried the drain pump out of itself while on the water. The contents of the bag emptied into the bilge and created enough standing water for it to get into my transmission.

I went to a Fly-High fitting with a flow rite and about a 3" section of hose to connect the drain pumps to the bags and this has been a lot safer. This unfortunately has introduced some priming issues on drain though.

3/4" NPT screws into the Fly High bags a little bit better but not as good as FlyHigh's own fittings. The advantage of using a PVC 3/4" extension is that you can "weld" it to the bag with PVC cement. The pump material is chemically incompatible with PVC cement and doesn't bond. I've tried. The 3/4" NPS pumps will screw nicely into the female NPT PVC fitting.

2) I found that the T800 pumps (and possibly the T1200) prime significantly better with the pumps oriented sideways with the discharge on the bottom and horizontal. They don't work that well in the orientation that all of the documentation shows (Sideways with the discharge pointing vertical). The second best option is for them to be vertical but even with the pump completely below the water line I still had the occasional failure to prime.

If the discharge isn't on the bottom and horizontal I've found that one burp of air will airlock them on the drain pumps. So, when the bags would get low and that first time the pump would get a little air they would stop pumping. If I was lucky I could power cycle the pump and get it to drain again. I usually ended up with 2-3" of water left in the bottom of the sacs (That's a lot of weight on a 750 lb bag). With the discharge at the bottom it gets 99% of the water out without having to babysit.

I'm doing more experimentation with the pump orientation before I make any "permanent" mods but what looks like the best option is a 3/4" PVC street elbow (NPT) glued directly to the bag and the pump screwed into that. Then I have a Flow Rite quick release on the discharge side and a quick release SAE connector for the wiring. So, if I want to remove the bag I remove the pump with it.

Good info, thank you.

I'm going to have to revise point number 2 above after further experimentation. That orientation seemed to be more tolerant of the occasional air gasp resulting in a more complete drain of the bags but it ended up priming less consistently. Not sure about the physics behind this but I guess I'll have to go back to the drawing board about how to address my draining issues on my rear bags.

They worked great when the pumps were screwed right into the bags accept for the issue of the pumps being pulled out of the threads but ever since I went to this setup between the bags and T800 pumps I've been fighting priming and airlock issues:


FWIW "3/4" FlowRite, and Barbed Fittings are significantly smaller in ID than 3/4" NPS on the T800 intakes and what not. I assume that 3/4" NPS is based on the OD of a male fitting and all of the fittings are the size of the OD. The Flow Rite and barbed fittings are based on the ID of the 3/4" hose hence they are smaller. My point being that if you're going to use 3/4" hose and fittings like in the above picture on the intake side of the pump it imposes a significant restriction relative to the ID of the pump intake.

I may redo the whole drain operation for the rear pumps. I'm thinking about turning the bags around. I've currently got the drain pumps on the front of the bags because there's space under the seats to clear the pumps and this was the way WakeMakers recommended. I'm thinking about putting 1" fittings with a 90 and 16" or so of 1" hose so that I can mount the drain pumps low on the transom. I'll just cram the 1" hose over the 3/4" NPS intake of the pump and secure it with a hose clamp. I'll put the pumps low enough that the water will naturally drain to the pump.

I have mine in the bilge area below the bags and they do a pretty good job of draining. Sometimes they do not drain all the way and I'll turn them on while plowing water to help them prime and drain the rest while underway. That does the trick 97% of the time. I was thinking of putting the drain pumps closer to the bag with the drain adapter from wakemakers to help it drain all the way more frequently.

All of my bags have a T800 pump screwed directly into the fitting and sealed with 4200. I have never had a single drop leak, of course they aren't easily removable either.

Originally Posted by hunter660

All of my bags have a T800 pump screwed directly into the fitting and sealed with 4200. I have never had a single drop leak, of course they aren't easily removable either.

I've thought about using an epoxy or something but then I'm pretty much totally committed to these pumps. These are also on 750 lb bags and If I'm not mistaken you've got 400s. So, there is some more force at play in my application. I've got the pumps screwed directly into my bow sac and they've been fine too. In the rear there's more weight involved plus there's the higher temp of the engine compartment to soften the sac's threads.

I am.not really sure how u are getting priming issues on the empty side of it. I have my bags connected with flowright and a 90 quick release and the only time i ever lose prime for a second is when i am coming into the dock,the bags are 3/4 empty, and i juice it in reverse. I did saw off the threads as low as possible with the flowrite. My buddy also sealed his pumps to bag so that route works as well


It is super annoying though to have the different thread sizes and them be proprietary to fly high. I have no clue why flyhigh wouldn't make the thread on the bag the same as the pump for ease. Guess thats why they charge 7.50 a fitting.

Originally Posted by xstarrider

I am.not really sure how u are getting priming issues on the empty side of it. I have my bags connected with flowright and a 90 quick release and...

Can you describe your setup some more? Sounds like you've got them on the rear. if that's the case I assume you've got enough hose on there so that the pumps aren't under the sacs. Is that 3/4" or 1" hose?

I have 3/4 hose with a link to 1 inch then to flowrite as i glued my original 3/4 fittings into my bag with pvc cement like fly high said and cant break them loose. My 750 have 3 ports. My empty port is on the bottom towards rear of the boat. I have as small as section of hose as i can have attached to the 90 quick release then to 3/4-1expander/reducer then to flowrite. This puts the pump into the corner closest to the engine wall along the rear transom. I don't have a problem with pump getting smushed.

As long as i am on plane the bags completely empty. However if i am idling they dont completely empty the bottom holds very very little water. I think that this is do to the fact i have 550lbs of pop bags in the nose that cause the boat to ride a little nose heavy at idle speeds

Wakemakers also suggested I could possibly orient the bags your way with pump towards bow. I had some air get in there a couple times this way so oriented the nags w pump the other way. Zero issues as the pump fits perfectly in the corner .



Btw thanks again for sundeck mod. Its working perfectly. I did have an issue with one of the shockes ripping out of the feck with just screws as that metal was not very thick. So I unstapled my vinyl and istalled two backing plates and put bolts thru. No issues since and its rock solid

So, if I'm understanding correctly you have the pumps under the weight of the bag in the outboard corner with I guess about 8-10" of hose going from the drain fitting to the pump intake. And the pumps or the bags don't mind that arrangement?

Thanks,
Jeff

BTW by "under the weight of the bag" I mean that the bag fills the entire compartment and therefore pushes the pump against the side/rear of the hull. Not that you put the pump literally under the bag.

Yup. Even in my Xstar/205v/x1 there is just enough room. The key is to come out of the bag with a quick connect 90. I pushed my bags as far forward as i could. I imagine in your 230 you would even have bigger compartments. Believe it or not the pump doesnt get that much pressure put on it. When completely full i can still get a hand back there.

The other thing i did to prevent leaks and what not was to pvc cement my flowrites once i had them all oriented the way i wanted. I will try and get you some pics. What i found the best for me was to orient the top output arm closer to the center of the bag rather than on the outside. This allowed the pump to sit completely in the corner. If the top output was on the other side it would rest against the wall first and you would lose that inch to inch and a half space that is much needed to allow the pump to rest flush in the corner against the engine partition and the transom. Hope that makes sense. I have had my boat set up this way going on 2.5 seasons with zero issues.


Also the reason i have them on the engine partition sode rather then the outside wall is because my transom is curved. Its farthest back at the engine partition so that also gives me a bit of extra room.