For the purpose of this discussion, lets just assume that the house takes no rake.
For every $6 that you bet, you'll win $11 each time that you win. If luck breaks exactly even:
After 17 bets you will have won $11 six times, for a total win of $66; and you will have lost $6 eleven times, for a total loss of $66.
Therefore, if a $6 bet wins $11; then obviously a winning $2 bet will net you one third of that, or $3.67.