Re: What am I doing wrong???
It sounds like it would help if you focused on what the line is doing, rather than your timing. Good or perfect timing is not a set thing, it has to change in reaction to how the rod and line are moving. Watch the line and work on making it look the same while casting as when you were casting it with the heavier line. The rod will feel different in your hand, but try not to focus on that, but rather what the line is doing in the air.
That rod is by no means a fast or stiff rod in the grand scheme of things, but it is compared to a bamboo rod. Focus on making the line fly right and then develop muscle memory of how the rod feels in your hand as it is making ideal loops.
That rod is one of my absolute all time favorites by the way. You picked a GEM!