Quark UBEC for my Neu 1515 1.5y/s brushless system ; 5A or 6A? which way should I go?

[BrianG]

Are both those Feigao motors the same kv rating? Lower kv motors seems to have more of a magnetic feel. My Feigao 8XL felt way different than my 10XL. It is possible the magnet got weaker too. Excessive heat can deteriorate a magnet.

What speeds were you spinning those Feigaos? They tend to heat up quite a bit at speeds over 35k rpm, so you might want to look at that. If the coils haven't melted (or partially melted), you can replace the magnet (assuming that it is the problem). Either find one from the same type of motor from someone here, or see about getting a brand new replacement. Mike should be able to help you out if that's the case.