Kyle Busch called out Brad Keselowski on X following Monday’s FireKeepers Casino 400 at Michigan International Speedway. On the overtime restart, Keselowski strangely slowed up as he entered Turn 1. Keselowski, running on the outside line behind William Byron, backed into Busch’s front end, sending an accordion like effect through the field. Busch is still wondering “what the fu*k” Keselowski was doing. “What the fu*k was the 6 doing?!,” Busch tweeted. Keselowski’s issue not only stacked up the outside line behind him but killed the momentum Byron had going into corner. That allowed Tyler Redd…