Tank, you have committed a misdeed by setting the float bowl seat slightly lower, rather than replacing it. By doing that you lowered the float height, and you also did not properly fix the flooding problem, because the seat is still worn out. You also do not seem to have replaced the needle, which you said has a groove in it. Most likely the issues you now have, stem from that, combined with the fact that you have not yet tuned the main mixture adjustment.
You cannot expect the engine to run perfectly when it now has a low float height, an unadjusted main mixture control, and a slight tendency to flood because the needle and seat still leak. What you have sounds like the same faults you had in the first place, mildly alleviated because moving the seat may have slowed the leakage slightly.
I suggest you replace the needle and seat, then check the float height. When the flooding has stopped and the float height is correct, it is the work of a moment to adjust the mixture.
