prolly, you need to check current ratings on batteries to be sure....
tune: I mean "tweak" so use a pot for R1(I used 500ohms) and a pot for R2(I used 100ohms) so you can find a perfect balance for them(sweet spot), DONT TURN THEM DOWN TOO LOW THOUGH OR U CAUSE SHORT CIRCUITS, they dont need to be rated for such high power(wattages)unless you go over 12volts, there is a sweet spot that optimizes efficiencies(could be 230ohm, could be 210ohm)....... on mine transformer there were 2feedback coils(i forget which one is best)
On mine it runs 750mA on 2x 9v batteries(I think) , and 1.33amps on a 12v supply....
also I used 2x 2n3055 in parallel config(not darlington pair) to eat some of the heat (heatsink may be good alternative), on the supply you can only run for 30seconds-a min and it will get to 60 celcius hot...
.........and.........be VERY careful most fly-backs have internal rectifiers and caps, so make sure to read up on all HVsafety
& DISCHARGEING...... and dont go pulling on wires while this circuit is active!...........