Good evening,
The immediate problem is that the float/needle valve appear to be well hung-up and a cylinder almost immediately fills with gas when it is turned off, and it runs quite rich naturally. There is no fuel cut-off yet, which is job one.
Flooding a crankcase is bad...very bad.
While pretty rare, I have cracked a cylinder on an engine that had debris in the needle/seat and had flooded. The cylinder was instantly and throughly turned into scrap metal. It took about 10 milliseconds to do that too.
When I have flooding occur on a Magnum, I take the carb off and clean the needle, seat, and bowl. It is almost guaranteed there is crud in the bowl. The addition of a fuel filter between the pump and bowl will likely prevent any further issues.
Selection of a proper filter is paramount. I use Napa 3011 or Wix 33011 filters. They are a 12 micron filter. Other filters will let actual chunks of debris through as they are 80 micron or larger. Here is an example of what happens when a 80 micron filter is used. The carb shown below is a Nikkei.
The red powder is dirt from the Red River Valley, where this engine lived.
The brass piece is the main jet. No wonder it ran like crap.
Once the carb is cleaned and filters installed then I don't have to worry about shutting off the fuel. It can sit there for weeks with the fuel turned on without issue.