He's a 'mechanical' genius. [=he is a person who is very smart about machines]
He's not 'mechanically' inclined. [=he is not knowledgeable about machinery]
The flight was delayed because of 'mechanical' problems/difficulties.
(..) do is to believe. Then we haven't a moment to lose. Do you think Zeppelins are a bad investment? These mechanical birds will get our message out. They will go to an Internet cafe... ...and e-mail the remaining MasterBuilders... (..)2014 The Lego Movie