Video of the problem; http://youtu.be/h00GlKrCYG4?t=37s So, my present problem is this: I installed 4 AXi motors, and confirmed that they worked with a hover test, but then it went into serious oscillation when it had to correct itself. So I decided to try using a motor adapter and 9443 props instead of the carbon fibre ones that worked with the default adapters. I went out to give it a flight today, and the front motor visible in this video doesn't start as quickly as the others ... it goes back and forth a bit before starting to spin, and then it only spins at about half the speed in idle. I didn't catch, or notice this before take off and I think the quad got about 10cm of air in a flipping motion before biting the grass, which seems like a logical reaction to having a funky motor. Any ideas what the most likely culprits are for this?