I have 5K on the factory tires and they are garbage. The rear is actually cupping. Handling now sucks. Going to try PR2's. I liked the PR1's I ran on the 2005, so we will see how the PR2's go. Certainly can't be worse than the cheap imitation of the of BT-023 that Yamaha put on the 2013 FJR.
Fixed it for you!
The tires you currently have may say BT-023 and have the BT-023 tread pattern but they are just a cheap tire that Yamaha contracted with Bridgestone to build as a OEM tire and a long ways from having the quality of a real BT-023. Try a set of the BT-023GTs and I think you will find that they will have much better grip and handling, smoother ride, and will last a lot longer what came with the FJR.
Sad thing is the rear tire that is cupping is not the original Yamaha tire. That tire was replaced at 1K with a 1 inch slice. I replaced it with the same tire from the Superstore to match the front. I'm going to go with PR2's for now, but will keep an eye on others experience with the GT. Also, the PR4's are right around the corner, which will be out for the next replacement.