In 1974 Kharchenko proved that if a $ 0 $ -component of an $ n $ -graded associative algebra is PI then this algebra is PI.In the Novikov algebras of characteristic 0 the existence of a polynomial identity is equivalent to the solvability of the commutator ideal.We study a $ _{2} $ -graded Novikov algebra $ N=A+M $ and prove that if the characteristic of the basic field is not 2 or 3and its 0-component $ A $ is associative or Lie-nilpotent of index 3 thenthe commutator ideal $ [N,N] $ is solvable.
