electric lawnmower

[speedy]

Hi !

I'd like to convert my stinky old gas lanmower into a clean electric one :)
But i don't know what motor to chose? Would a Turnigy 80-100-B 130Kv Brushless Outrunner (eq: 70-55)
Motor on 6s be enough ? i,d like to get about 2h of runtime and eqal power as the 4,5hp 4-stroke engine stock engine .

For battery i was thinking of using a 7s4p of 8000mah li-fe pack .

the lawnmower has an 25inch rotor.