Preheat oven to 325 degrees F (165 degrees C). Lightly oil a baking sheet.
Bring 6 cups water to a boil in a saucepan. Add pumpkin seeds and salt; simmer for 10 minutes. Strain and pat dry. Spread seeds in a single layer on the prepared baking sheet; sprinkle chile powder with lime on top.
Bake in the preheated oven for 10 minutes; remove pan from oven. Stir seeds, spread back into a single layer, and return to hot oven. Repeat twice more, stirring every 10 minutes, until seeds are golden and crisp.