In order to get the maximum earn
from a racket you have to complete the specific side mission from the associate you assigned the racket to. Your first opportunity to do so is when you assign the first racket to Cassandra
. You will meet Emmanuel Lazare
that will introduce you to optional mission "Are We Cool"
. If you accept the mission you will have to steal a boat with weed and deliver it back to Cassandra. When you do it twice the achievement will pop and the racket will have maximum earn.