Combine jam, vinegar, and chili powder in a blender. Mix until smooth.

Put chicken in a large zippy bag.

Pour the jam mixture over the top, reserving half a cup.

Seal bag and marinate in the refrigerator 2-4 hours.

Remove chicken from marinade.

Discard marinade.

Grill chicken over medium heat 8-10 minutes per side, basting with reserved marinade.