What's the ambient temperature? What time of day are you fishing? What water body type are you fishing.
I have had much summertime success fishing lakes with a 4# TFO rod lined with an SA Sharkskin 150 grain sinking line with a 14" leader and a 10" tippet. Landing bass between 2 - 5 pounds. I can cast to the shoreline, under piers, and not wait long before retrieving, or I can cast to the slope/gradual drop-off, wait a bit longer, and begin my retrieve. Heat of the day doesn't play a big factor when I'm rigged this way.
Here's to bent tips and happy days!
2018 Women's Director Texas Council FFIFishOn! the Fly