I had the same hard to start problem in 1978 with my C152.
The problem was Cessna only installed a single primer to the #2 cylinder of the Lycoming. This was a common thing for Cessna to install only one primer nozzle.
If you over prime more than two shots on the single nozzle, then that cylinder is flooded and the other three still didn’t get any fuel.
Another thing is the carbs of 1978/1979 Cessna 152s did not have an accelerator pump (like old Stromberg carbs for C-65/75/85s).
Cessna had a kit with the other three primer nozzles, lines, tees and hardware to install lines to the other three cylinders.
I installed mine years ago and that took care of the hard starting problem. It is running by the time the second blade passes by — winter or summer.
I just did an annual inspection on a 1969 Cessna 172, Lycoming O-320, it was just purchased by someone on the field. It did the characteristic poop-poop-poop-bang over and over. After removing the cowl, I pointed out the single primer to the #2 cylinder and advised adding the needed primer lines.