Is it possible to put 125cc gilera runner engine into aprilia sr50 factory?

[AndewMozajvek]

Hi, i have aprilia sr50 factory [50cc] and i would like to know if there is any posibility that i can put engine from gilera runner [125cc] to my aprilia.. and i saw some aprilias same as mine with engine 125..

 

[BobA]

They may look the same but the engine won't fit