7000 feet? Think really small fuel jet.
Somewhere I read a thread about a guy that stripped an end off of a bread bag twisty tie to expose the thin metal wire. He then removed his fuel jet from the carburetor and filled it up with solder using a butane torch to heat the jet. Before the solder hardened he stuck the wire in the solder, all the way through the jet, and held it there untill it cooled. Pull out the wire and you have a really small fuel jet. If it is too small you can use the wire like a ream and slowly enlarge the hole.