I have a zagi with a tornado brushless motor with a 25 amp speed controller. The prop is a carbon 5*4.8. Batteries are 8 No. 2100 Mamp batteries.

Problem is it has hardly any power to fly? I am wondering that my prop isnt right? Does it matter whether the prop is a pusher prop or a reversed standard prop?

mounting a standard prop backwards does not make it push the air in the other direction, it just makes it push the air poorly in the same direction. So, if the current prop is pushing air in the correct direction, then it's not that.

Beyond that, I know very little about electrics. If you don't get an answer here, you might try in the electrics forum.

Brian,

Tell us more about your prop orientation and the direction it turns when looking from the rear of the Zagi.

Does it rotate clockwise?

Is the raised lettering on the prop facing the motor?

Both answers should be "yes".

Looking from the back the prop turns clockwise and the lettering faces the motor.

Ok, that's a good start.

My next area of concern would be your battery pack. Can those cells deliver the current you need for the Tornado brushless motor?

Do you know what type of cells they are? Were they matched up with that power system?

My guess is that you want to draw around 20amps at full throttle.

Have you cycled the battery pack a couple times?

In this case, cycling the pack won't help enough to make a difference, UNLESS the battery wasn't charged in the first place.

What are you using to charge the pack?
How long does it take to charge?
What charge rate are you using?

You should be using a peak-detect charger capable of charging 8-cell packs. The charge rate should be no more than 2.1 Amps, and the charge should take about an hour at 2.1 Amps. Divide the capacity of the pack by the charge rate to get an approximate charge time.

My suspicion is that these "2100mAh" cells are high-capacity AA cells from Wal-Mart or Radio Shack. These cells are not designed for high-current applications like R/C airplanes; they're designed for digital cameras and toys. You'll be lucky to get 5 Amps out of them, let alone 20 Amps. It's best to stay away from AA cells in general for electric flight.