Yes, the YICS chamber is prone to age related leaks. I would remove it entirely while I had the chance. It could test OK today, but later a leak would manifest itself. The YICS seemed like a good idea at the time, but even Yamaha decided it wasn't worth the expense and hassle and eliminated it on the 1300.
When the engine is out, it is short easy work to completely remove the YICS chamber. Just makes sure to either make a 'Jason mod' to the remaining open ports or plug the ports.