i see several post here about slow sticks. i am having an on going problem with mine, i hope someone out there can help.
the problem;
the stock motor cut off after a few seconds of full throttle either in the air or on the bench. here is what i have tried doing to correct the problem. tried a new motor and gearbox with the same prop, tried new lipo battery packs, 1200ma and 1500ma both 7.4 volts. i even tried putting 2-1200ma in parallel for more current capacity. put in a new 20 amp speed controller and it still cuts off after a few seconds.
with the throttle at almost full, the motor is pulling right at 6 amps, the pack voltage is around 6.5 and watts are 36 to 38. nothing is hot, motor or speed controller. the radio a jr 8103 and is/ was new at the start of this adventure. the batteries are charged with a triton charger.
any one with any other ideas?

I don't understand how you can replace an entire power system and still have the same problem, unless some of the parts don't match.

If the voltage is down to 6.5 Volts at only 6 Amps, something is very wrong. These batteries should be holding at least 7.5 Volts if they're any good...

Where did these batteries come from? What are their C ratings? I'd go as far as putting money on your problem being related to weak batteries.