Dave,
I replaced a steering system a few years back and it made all the difference. That is all I know about that so I will shu tup about mechanical issues. As far as your lack of fish...remember this beautiful piece of advice, "Never Leave Fish To Find Fish." It is often hard to adhere to but it is great advice. If you hit in Centre Harbor.....stay there. As far as the rest of your releases it sound like late last year when the salmon seemed to be short biting. This could be a good sign that things are about to turn around on the big pond. Towards the end of last season the bite was absolutely fantastic, then the short bites happenes then th bite was gone. I am hoping that the spring will happen in reverse!
Good Luck with the TUBB!