happened to me with a different brand but exact same thing. there was a blown gasket way down in the bottom where the carb. mounts letting air in and kept sucking gas the only way I could shut it off was to bury it forcefully in to a big log.
kp
October 2016
take the blade off, try adjust the idle adjuster when running with the chain blade off.
m
April 2016
Automatic Answer
While you wait for answers, we may have found some information which could help you.