Is it racist to kill more black men than white men?

It is racist to kill someone because of their race.

If, for instance, you were minding your own business and an armed group of three Black men and a White man tried to rob you, and you somehow killed all four, then that would likely just be self-defense.

However, if you mean more in a police context, and more men of one race are killed, and there is a pattern of this happening, then that would be suspicious and very well could be due to racism.