When i try to start my yamaha atv it wont cranks it just buzzes Help pls?

Its a 1986 Yamaha moto4 225cc and i just bought it and when i use the electric start wont turn the crank but when i use the pull start and pull it a little then use the electric start it moves then stops and starts buzzing pls help|||it sounds like the starter has a dead spot.|||You say battery is new but have you checked it is charged, it may have been 'standing' for a while.|||New battery to start with! (pun intended)|||Could be your Starter or solenoid. Have them checked