Seagull Edge 540 67" & 78"

[gdwyer]

I have both sizes of the Seagull edge 540, 120 & 180 and need help with both please.

I have 3 basic sizes of battery, and 4 of each
6S 5200mah 20C
6S 2500mah 30C
3S 2100mah 25C
I have 99 & 80amp ESC, both by hacker
I have E-flite90, Actro 40-5, and Hacker A60-16L
I have 21" and 18" APCE and 16" Aero Naut props

On the smaller one (120) I have been running 6S 5200mah lipo, 80amp Hacker Opto, and e-flite 90 motor, with 18x8 apce prop, having changed from an Aeronaut 17x10 carbon previously. I could get 10 min flights and still have 35-40% left in the large 6S.
I never had MAD power, but could loop and immelman etc, but since the change of prop, but possibly for other reasons ( slightly bent prop shaft?) it is very low on power, so much so that now it cannot complete a loop. Maybe the vibration from the shaft has demagmetised the motor?
I have just got an Actro 40-5 to replace the 90 sized eflite, and am planning to use it in the 120 Edge with the 80amp controller, 12S 2500, and a 16x8 carbon prop. What do you think? Should have shorter flight time but lots more power? 8 mins would be loads and the 12S setup should be same weight as the single large 6S? Any advice for me? The model comes in at 4.5kg with the large 6S on board.

On the larger one (180) I have set up Hacker 99 amp Speed controller, with A60-16 motor, 21x10 APCE and the same proposed 12S but using the smaller packs ( the two 5200 packs put the model up to 7.5 kg! )

When running on the ground, I only get 4-5 mins of power at 50-75% throttle which is too short, but the larger packs weigh a ton! Help!!
How can I get more time using the components I have?

Any help on either model much appreciated,

G