Aray, I flew my Javelin with YS 63 using 12x7. Depending on what you're used to, it may seem like it's going a bit slow on the uplines, but it will pull indefinitely. I can't recall trying the 11x9, but I think 12x7 is the preferred size. This is a great combination, by the way, and an excellent first pattern model. I presume you fly with the Cape Ann club?