man, that sucks! i fried my 9920 right after i got it, had it warranted for free, got it back and then after 3 runs my lehner xl3100 dies. i know how you feel.
Well at least I found the problem (I mean Serum did), the bad thing is more $$$. I have to buy a whole new BL setup. My BEC wires got all burnt up also.
So how do I stop this from happening again? With 2 18.5 4200mah lipo's on there I cant have another fire.
the problem finally presents itself, huh! It seems as though the sand has caught up with you, Ryan. It is hell on bearings, and it just happened to destroy the one bearing that was holding your BL system together!
All 7xls from RC-Monster will be the Wanderer version(out of Feigaos, so will replace with wanderers). 8xl is also a good recommendation for your setup, Ryan. Here is another tip - put a drop of opil opn the bearing, then place a piece of scotch tape over it to keep the dirt out. This will keep the bearing in top shape for a long time, even in harsh conditions.
Oh, this sucks. Never saw a bearing like that on a motor. Reminds me of skateboard wheels, and I had a knuckle bearing like this recently.
The scotch tape trick is a good idea. I always covered my Wanderer/Feigao back bearings right off the bat, and keep them oiled. (less is more, there)
Loosing both, ESC and motor, at the same time hurts. I hope you'll have some better luck with your next setup.