Does anyone know why the Hacker A60-6XS v2 is listed for 6S and the A60-7xs v2 is for 8S they look a lot alike in there specs???

They look the same but are different kv. 370-320, you could use them on the same plane but could use 6s with the 6xs or 8s with the 7xs. I know they can both be used on the SebArt MythoS 125e. The 6s will pull a higher amperage for the same power as an 8s set up.

what if you flew it with 8s on the 6xs motor more voltage = less amps= less heat ????

Maybe it will work with A60-6XS and 8 cells:

http://www.rcgroups.com/forums/showthread.php?t=2000545

I use A60-7XS with 8 cells and 19x10 (Falcon Electric carbon V2 prop) on a MythoS 125E. Works very well.

/Bo

You could use 8 cells on the 6 cell motor but you would have to decrease the prop size so as to limit the amp draw.

8 cell on the 6xs would make the rpm higher than it was designed for so you would have to run a smaller prop to compensate and most likely it would run hotter than it should. That's why they have the two different motors, with the 8 cell you could run say 4500 packs were you would need 6000 packs for the same flight time.