BOSTON — Saturday night, Frankie Montas completed a full, encouraging turn. The Yankees may be struggling scoring runs, holding leads and running the bases on this road trip, but at least their starting pitching seemed to get back in line. After a tumultuous couple of weeks, the Yankees’ rotation went one turn through with a very respectable 2.61 ERA. It’s a good sign for the Bombers as they go down the stretch of their final 48 games of the regular season.