I am a software engineer and don't have much knowledge of mechanics. I want to build a quadcopter that can lift about the wieght of a person say 100 kgs. I am thinking of to use a 125cc bike engine for power and gearbox for related speed change requirements. So the total weight of the drone could be around 150 KGs including that pilot I talked above. I want to know Will it be possible practically to build in such a way? Would the engine be able to provide required speed and RPM? What size of propallers should be?