yeah, a possiable leak.
I generally use sealent and Blue loctite on the back plate to minnize that.
Maybe try re torqing the head screws.

maybe try reaming the air breed hole with a guitar string to clean it.

Mine is rear needle , so to makesure the orifis is clean or the high side, I had to remove
the barral's arm.

Before you take the carb apart...try checking the fuel tank to see if the clunk didn't get
sholve forward during the dead stick landing.