Dumb question, but do you have enough backing on the reel? The last time I've seen that much coil was when I bought a used outfit where the guy put a perfectly good SA line on the reel with zero backing.
It coiled like a phone cord and no amount of stretching would save it. If its a question of not enough backing one perk of a WF line is that you can trim off a few feet of the running line with no harm to casting unless you're trying to throw ninety feet. One thing no one has asked. How far, and with what size flys are you trying to throw?