CREATE TABLE table_name_90 (wins VARCHAR(255), year VARCHAR(255), class VARCHAR(255), points VARCHAR(255), team VARCHAR(255))
How many wins for bikes with under 54 points, team yamaha, a 250cc bike, and before 1977?
    
SQL: SELECT COUNT(wins) FROM table_name_90 WHERE points < 54 AND team = "yamaha" AND class = "250cc" AND year < 1977