Motorcycle wont start?

so i bought a bike for dirt cheap it was running ok at the time when i first got it my buddie goes to tear off the head all that good stuff well we had to take off and covered everything good we got home put it back together just fine but come to find out my buddies lil bro tryed to kick it while the head was off and now it wont start so could his lil bro done anything from just trying to kick start it with the head off and if so what and what do i do thks