I bought a used Toro gts 6.0 personal pace self propelled mower,we noticed gas leaking out of the muffler,what's happenng is there are 2 screws that hold the muffler on,well we took out 1 screw and gas was coming out of the screw hole,what's casusing this to happen? So far I have rebuilt carb,replaced air filter,replaced spark plug?any help would be appreciated.

Needle valve in carb is not closing all the way .
Did you blow through the carb with air ?

Hi DG:
I want to thank you for taking time out of your busy day to answer my? I really appreciate the feedback,I'm going to try what you said,as it seems like the only problem it could be,do you agree?
Thanks again
Bill.

Its in the carb forsure.
Check tip on needle
Check seat.
Check float level.
Don't blow through the fuel inlet , you could blow out the rubber seat.
Luck
Luck