dreaded gas tank cracks, what do they look like?

Small vertical cracks? Not mine! Started at about 12 o'clock at the BASE of the threaded filler, around CCW to about 7 and both ends trail off into the tank body. This is the most serious crack. Another starts at 6:30 and continues to about 4. The first , big one now is open to the inside and leaks like a sieve. Same crap tank? I see lots of KDX's out there at races and nobody's shouting (except me) one way or the other whether their's leaked and they replaced. I'm not going to risk $300 on Kawi replacement, I'm going IMS even though I don't feel need for larger capacity.