Hey everyone, here is the last update on this saw for now. In short, it is running good now, no more flooding issues.
I decided to start over and completely clean and rebuild the carburetor again using the best parts from both of the ones I already had, as well as a brand new check valve kit. I made sure I used a float diaphragm with the proper sized nub on it, and I also followed Tony’s advice and set the needle valve lever a bit lower than the carb deck. I pressure tested the carburetor after it was put back together and it checked out. I also did another compression test on the saw to make sure that was right and it was in the 150 psi range, so I’m not sure why I was so off on the first test but oh well. When I started the saw, it immediately stayed at a steady rpm and I was able to adjust the screws and get normal results. Now all that is left to do is to tune it properly, but I have to wait until tomorrow to do that because I don’t want to wake up the whole neighborhood! Lol.
This problem was a bit frustrating for me, but it turned out to be a bit of a simple solution, as is what often happens to be the case. At least I was able to gain some knowledge from it to use in the future. Thanks everyone for your help and advice, it was greatly appreciated.