Stir together papaya, orange juice, and pectin in a very large pot over medium-high heat until it begins to boil. Stir constantly as the mixture heats. Once boiling, stir in the sugar, and return to a boil, stirring constantly. Once the jam has returned to a boil, start a timer, and boil for exactly 1 minute.
Ladle the hot jam into the hot, sterilized canning jars and seal with lids and rings. Allow to cool to room temperature, and refrigerate any jars that do not seal.
