ct420 With your tail motors wired in parallel you are essentially adding twice the load of a single motor to your esc, if it wasn't for the lightened load your 4 in 1 would burn out very fast so its good that you have a fuse. A definite benefit of having the motors in parallel that I'm not sure you've realized yet is that you will be able to land your heli if one of the motors blows. Pretty much the only thing I would do to you mod is move the fuse towards the middle of the heli to balance it out a bit more.

Does anyone have pictures of the ducted tail mod? I'm really interested in seeing it.