BJ29, how do you hold your lipo's down??

[SloHD]

Well I didn't think to bring my temp gauge the first couple runs before the modding. With my fingers, and experience from onroad racing, Id say it was about 180 or so. But I have temped it with the scoop mod/fan and It dropped to 120 ish after 5 mins running. Opening the scoops have made a big difference. Im sure the bigger bullets will help as well. And I plan on getting a better fan. :)

[lenny]

180F on a stock setup ?

Something does not add up.
Are you sure you have good water flow ?
I know that some of the nipples came right from the factory a little bit blocked,
To no flow at all.
From silicone and metal in them, Rudder inlet and outlet to.
Can you show the setup with the cells in place like rtr ?
Also hardware setting to.

[SloHD]

Well it could have been a little lower, that was a guess with my fingers. It was setup like the pics above with the lipos. (2) 2s in series. That was also with the x642, not the stock prop. With the stock prop it wasn't as hot. And yes I found the silicone build up in the nipples and cleaned those out as well. Also I have since rotated the jacket so the exit nipple is on top. (Not like the pic I posted) I believe that has all helped as well... And the strut is setup just a tad higher than level on a flat table, with a slight negative/down angle. (I thinks it's negative...?)

[lenny]

Ok,
Good thing you checked all that stuff out.

[tlandauer]

Yes that looks good,
I see you cut the rail some to.
Does it make it a little easier getting the packs in and out easier ?
That is what I was going the do next.
And also I was going to get rid of the trays so mine 4s 5300mah genace will fit in the sponsons to,
Also to lower the CG in the hull to.
When I was testing I just had the cells wedged with a small piece of foam and the and this neopene wedge,
And it held good in the flip to.
But the motor moved a little to the starboard side.

The cells are 4s 40c 4000mah packs in this picture below.
[ATTACH=CONFIG]99097[/ATTACH][ATTACH=CONFIG]99098[/ATTACH]
37"Daytona.
[ATTACH=CONFIG]0[/ATTACH][ATTACH=CONFIG]99099[/ATTACH][ATTACH=CONFIG]99100[/ATTACH][ATTACH=CONFIG]99101[/ATTACH]

Thanks for the pictures, I think because I use 5000 mah Lipos and those 4s are thicker than the 4000 mah you use. It is difficult for them to get to the sponson, once they are in, they move back and forth freely though.
I also used a Dremel to grind down the wood on the side of the motor mount.

[bikergreen]

Turns out I didn't have a very good look when I pulled my MG out of the water.. One of the batterys must have smashed the inside of the hull pretty hard, probably the one which actually split the battery tray in half. I now have a pretty wrecked hull, I will patch it and use it as a beater I think.

[tlandauer]

Turns out I didn't have a very good look when I pulled my MG out of the water.. One of the batterys must have smashed the inside of the hull pretty hard, probably the one which actually split the battery tray in half. I now have a pretty wrecked hull, I will patch it and use it as a beater I think.

That is exactly what happened to mine, although my split was a little shorter than yours.
First thing I did was clean inside, use acetone to clean , you need to really rub it in until you feel the FG is getting sticky. From the outside, I chipped away any looser paint, then I try a dry run to " Massage " the hull, I want to see in which way would it go back as smooth as it can, remember the steps. Now, use medium CA, ( not thin CA, it dries too quickly), drip sparingly along the open seam, try to duplicate the steps to " massage" the hull back. Let cure.
Only after the outside is done do you want to attack the inside, I epoxied it with a strip of FG tape over the seam.

[bikergreen]

That is exactly what happened to mine, although my split was a little shorter than yours.
First thing I did was clean inside, use acetone to clean , you need to really rub it in until you feel the FG is getting sticky. From the outside, I chipped away any looser paint, then I try a dry run to " Massage " the hull, I want to see in which way would it go back as smooth as it can, remember the steps. Now, use medium CA, ( not thin CA, it dries too quickly), drip sparingly along the open seam, try to duplicate the steps to " massage" the hull back. Let cure.
Only after the outside is done do you want to attack the inside, I epoxied it with a strip of FG tape over the seam.

Well that makes me feel a little better :p Thanks for the tips on the repair! I will give that a go and hopefully save it. That was a bummer for sure, wish I had reinforced the inside of the hull with resin or epoxy before I started hammering on it.. doesn't help that I'm running it hard and fast with CC 1515 in it..

[tlandauer]

Well that makes me feel a little better :p Thanks for the tips on the repair! I will give that a go and hopefully save it. That was a bummer for sure, wish I had reinforced the inside of the hull with resin or epoxy before I started hammering on it.. doesn't help that I'm running it hard and fast with CC 1515 in it..

I had the same experience, after the flip, I saw the trays were loose, but I continued to run for another set of batteries. never saw the seam was wide open, guess the boat was running pretty fast and the seam was above the water line, lol... Not a drop of water inside!! ( the boat did a 360* flip, never needed to retrieve it)
I also cleaned out the flimsy foam ProBoat installed under the front deck, used two-part expanding foam from Kintec, it worked well, was not as complicated as I has thought.
Well, you got a great motor in there, I just bought a CC 1515 and haven't tried it yet.
Good luck on the repair!

[Seayall]

Just got a BJ29, first time out with 6S 5000mah & did the same thing. Battery mounts, motor mounts & all broke loose. (But still allot of fun!)
No hull damage. Appears from this forum that I can just epoxy & re glass the wood back in. True?

[macace123]

yes you can i cut my sides down so they fit lower in the boat it will help with the CG and they are at a slight angle. and if you have the time i would reinforce the inside with fiberglass cloth cause once it takes a hit it does delam so be cautious.

[Seayall]

yes you can i cut my sides down so they fit lower in the boat it will help with the CG and they are at a slight angle. and if you have the time i would reinforce the inside with fiberglass cloth cause once it takes a hit it does delam so be cautious.

I epoxied everything back together then laid glass cloth everywhere I could, trying to strengthen the motor mount area out to the battery mounts and up the hull.
Did a little sanding on the bare glass areas of the hull to insure a better bond. During re assembly I noticed the prop nut was loose & allowed the prop to move up &down and side to side on the shaft. Did running it with the loose nut wallow out the end of the prop?

[skeeler]

Can anyone offer any guidance on removing the battery trays? I'd like to run 4S 5450-mAh batteries in each sponson, so I need more room.

[skeeler]

To answer my own question, you can pull the trays out with your fingers and thumb. They pop right out. I'm very impressed with how poorly they are epoxied in place.