Stop in for a cup of coffee

just poured into the bores (sorry I fell asleep...long day)
So there may or may not be fuel in the bowls. What you're doing is enrichening the fuel available to the cylinders. That job should be done by the choke and the accelerator pump. (Whenever the throttle is moved from idle, the pump should mechanically shoot fuel into the barrels. You can see that with the air cleaner off and working the throttle. Should be enough fuel in the bowl for a bunch of pump shots.)
If there is no fuel in the carb or fuel line.
check gas cap. Return line to tank. Does it have one of those charcoal canisters. Not familiar with that models sounds like fuel is draining back .

I think OMR is right. See what's going on right before or right after you shut it off.
Maybe some leak that's contributing to the issue.