I'm more than confoozled today. I know nothing about this recipe, and have added cautions in ( ) from other sites, but to counter Bob Marley, here's a more palatable jam:

SWEET POTATO JAM

Sweet potatoes, 1 kilogram (2.2 lbs)
Sugar, 2 cups
Cinnamon, 1 stick
Cloves, 2
Grated orange peel, 1

Cook sweet potatoes with the grated orange peels. Peel them and strain to avoid sweet potato fibers. Mix the sweet potato, sugar, a piece of the grated orange peel, cinammon and cloves in a pot. Put it on the heat and mix it until it acquires a jam consistency. Continue mixing so that it does not stick on the bottom and remove from heat. Bottle it hot (in sterile jars) and let cool. Place in refrigerator (perishable, not a good keeper). (When a jar is opened, serve within a week).
Sweet Potato Jam

In the foreign food sections, Filipino purple yam jam (Halayang Ube) may sometimes be found in jars. There also are Caribbean yam jams.

American Yam Jam may be ordered from this supplier of Cajun foods:
Yam Jam
Ingredients- Sweet potatoes, brown sugar, corn syrup, lemon juice, vanilla extract, spices, orange extract.