Your reel isn't big enough? While a musky are an ultra strong fish, they aren't neccessarily big runners. It's not a fish that will take you very deep into your backing. Most of their runs are very strong, but short. The only problem you will likely run into is the size of the wet sock you will be limited to casting with a 9 wt rod. Like Dan said, upgrade yourself to a 10 or 11 wt and you will be happier in the long run...!!!