I received my Flightpower 4s 4350 in the post yesterday, I ran the storage charge down at low throttle then charged up and ran it hard, from the start I thought I had blown something, it accelerated away slower than before and released a puff of smoke, I ran over and disconnected finding that the smoke had stopped and everything was still cool, it turns out the pinion had slipped and was burning off the threadlock causing the smoke, a quick reaplication of threadlock and retightening the grubscrew with the other end of the allenkey had it going again.
Holy [expletive of your choice]ing hell this things FAST and then some, easily half as fast again over the old setup despite the smaller tyres, I may get used to the power at some point but for now I think a 3s pack would have been enough, I need to set up some punch control on the MM and put my throttle thumb in some serious precision training as it will spin the wheels at what used to be its top speed.
here's an overview of my first hard LiPo run.
and one that show the Voltage bertter.