I'd eliminate the foil and raise the temp a bit (depending on what temp you're cooking at already) or put over some hi heat like ron said.
It's not the skin that is the problem, it is getting the fat to render out.
22" WSM & Kettle
Former owner: Jambo, Klose BYC, Med. Spicewine, Pitts & Spitts, XL & (2) Med. BGE's, (2) 18" WSM's