Jiffy Auger

I have a jiffy model 30 gas auger. Bought it new last year. It keeps stalling out I believe it’s running lean. When I prime it it ran better for a short while but eventually bogged out again. The two screws inside the air filter that hold the carb on keep loosening up. Initially when I tightened those it seemed to help a little. I now can’t get it to start at all and gas keeps leaking out of the small hole on the top of the gas cap. I don’t recall their being a vent screw or anything but maybe there was something plugging it that I lost along the way? Any help/suggestions are appreciated.