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barmonkey
04-16-2009, 11:57 PM
Hello All, I have been trying to figure out where I am getting all the extra water from. I have followed Darin's "Race Prep Thread"...but I am new to the sport so I haven't attempted the mods that he performed on his hull. I have tried everything that I can think of to eliminate as much excess water, but still have copious amounts of water in the hull.

Forgive me if you have read this elsewhere, but I have also posted the following at RCU and RCG....

"OK, I have ten runs so far, and it's been fun...but I'm still getting some water in the hull from somewhere. I am really confused as to where it is coming from. As I have stated before: I used a bit of sealant at the strut mount, removed the fake exhaust and taped a piece of foam to the hole in the back of the hatch, and have used a generous supply of hatch tape all the way around the hatch. Now I am sure a bit of water can get in, but not this much!

I have also had one run where I didn't use any hatch tape...and actually forgot to put the drain plug back in...and there wasn't any perceptible gain in water accumulation. I haven't used any sealant on the Rudder mount or the turn fin mount yet BTW. Perhaps I am wrong, but, I just don't think that these areas are the problem as they spend very little time under water.

That leaves the motor's cooling jacket...I have done a flow test using a syringe with no leakage. That is, until I close off the pick-up holes on the rudder. This only yields a slight hiss of leakage. Is there that much pressure generated while it is running?

On the last run, I tried my best to keep it at 1/2 to 2/3 throttle (just enough to keep it on plane) for two laps. I still managed to get a lot of water in the hull...Suggestions!?!"

egneg
04-17-2009, 01:31 AM
I don't know the speeds you are running at but I have seen the tubes blow off from the water pressure so the cooling system very likely is to blame.

barmonkey
04-17-2009, 02:19 AM
That is certainly what I am leaning toward...cooling system leakage...just wish I could get in there and "see" what was going on...

I suppose that I could disconnect the cooling system for a short run, with the hope that I wouldn't overheat anything. That's the only way I can see to isolate the problem...

eboat
04-17-2009, 09:14 AM
That is what I would try unhook the water pickup and do a couple of laps and see if you have any water

I am having the same problem with a nitro Llumar converted to electric

The last thing I did was to put a piece of soft fuel tubing over the end of the stuffing tube just before the motor coupler . The flex shaft still had to stretch it a little to get through and I had a lot less water in the boat (still some but alot less)

Doug Smock
04-17-2009, 12:03 PM
Consider putting paper towels in suspect areas and run the boat a few seconds. This may help you narrow it down without taking the chance of harming equipment.

Good luck with it,

Doug :tiphat:

barmonkey
04-18-2009, 10:33 PM
Thanks for the input all...even those from my other posts on the other forums (RCU & RCG).

Doug, unfortunately I am not dealing with a bit of dribble or spray...I am getting a lot of water, so the paper towels would end up floating around in there!

I will try the bit of tubing around the stuffing tube/drive cable for now.

BTW I did run today...just made a couple of small circles and brought it in. I removed the tubing from the water pick-up for this, so any internal cooling leakage was eliminated. I still had water pour out of the drain plug after running.

detox
04-19-2009, 05:21 PM
Cracked hull?

Fluid
04-19-2009, 08:37 PM
This is rather rudimentary, but have you done a bathtub test? Tape up the boat just like you will run it (no reason to have the packs in) and submerge it in the tub full of warm water. Hold it underwater for a minute. You will see where the water is coming from by the trails of bubbles. If you see no bubbles, then my guess is the stuffing tube/driveline is pumping water inside. But I bet you see bubbles.



.

barmonkey
04-19-2009, 09:58 PM
I have done the bath tub test...But I haven't actually tried to drown it yet. I did find that the strut mount was leaking, and it seems that fixing that cut the water in half.

There is a small crack forming behind the left wing support which needs my attention before it gets out of hand. Water does leak out of this, and I assume that some can get in, but this is on the top of the boat. I just can't see much more than a dribble from that.

I was hoping to get that tubing around the stuffing tube/drive cable today, but it may be a few days before I get to run it again anyway.

Punisher 67
04-20-2009, 04:03 AM
I had the same problem in a Jetstream 800 brushless retrofit , it was a piece of silicone tubing that had a small cut in it , the boat would come back with almost a cup and a half of water in it , I yanked out all the silicone tube and replaced all of it with vinyl tubing . problem solved

barmonkey
04-27-2009, 10:36 AM
I finally had a chance to run again on Saturday...this time the only mod was to install the tubing around the stuffing tube/drive cable.

I found some old aquarium tubing that did the trick. I removed the collet to get a little more room to work. It was kind of a bear to get it around the stuffing tube, so I placed a hex key in the aquarium tubing to stiffen it up while I eased it around the stuffing tube. I used a bit longer length and then trimmed it back when I reinstalled the collet.

It seems to have worked but there was still water in the hull....but not near as much as before. The source this time was obvious! Tubing was cracked at the water jacket. There were no leaks in the cooling system when I headed out to the lake. I probably did this while installing the batteries, as that connection sits right at where the battery is.