Ok I have a problem with my Zagi 400. Its the stock equipment (its fairly new stock equipment actually). On a fully charged battery I get about 1 second of power before the BEC turns the motor off.

Any ideas as to whats wrong?

What kind of battery are you using with it and how old is the battery ? Also what is the cut-off voltage on the ESC and can it be adjusted? Does this happen only at the full throttle ?
It might be that if you're using old low C lipo cells with high cut-off voltage, the cell voltage can go under high stress below that, even when fully charged. Secondly you might have selected the wrong battery type or cell count for the ESC (if they are selectable).

These batteries are the standard packs that come with the Zagi. They arnt very old and dont have many flights on them. They're 8 cell 1700mA NiMh packs. AA size cells. They're 9.6 volts.

This is the same type setup I've been using on it for 6 years and this is the first time I've had a problem with it.

Edit: Forgot to say, this is a brushed system with a 400size motor.

Have you checked the connections between the battery and the ESC ? Loose connections might cause a lot of resistance and therefore voltage drop. Also have you checked the battery voltage ? It just might have one or more dead cells.

There dont seem to be any loose conections...And the same thing happens with all 4 of the batteries so I dont think its a battery problem.

I just thought...the motor wasnt broken in before it was fixed to the plane...I had never heard of breaking in an electric until just last week. The problem with the Zagi started months ago and breaking in the motor didnt even cross my mind. Now, to REALLY show how little I know about electrics, is this even a problem? I've heard from some people that its absolutley necessary to break them in, while Ive heard from other people that it makes no difference.

Running-in brushed motors will make the brushes have better contact (they will contour the communicator better) and therefore a little more power and longer life for the brushes. So if you have run your motor for months, it just might be that the brushes have worn out. Can you try with a different engine ?

This motor only had about 8 flights on it before the problems started. But, ya I'll probably just buy a new $9 motor for it. I love how cheap brushed stuff is.

As for trying another motor right now... the only other electric motor I have is a 600 size brushed. Is it even possible to runn a motor of that size on a stock Zagi 20amp speed controller?

Edit: Nevermind I found out that motors current draw is 26-28 amps....

Edit 2: I found another page which puts the motors draw at 17-19 amps...which is right?