Small Engines (Lawn Mowers, etc.): snowblower w/leaking primer button, vent hole, fuel tubes

Question
This is a scrapper blade type blower Homelite (jacobsen) "snoburst" and seems to run fine except fuel dribbles out the primer bulb's vent hole while it's running.  Carb is on top of engine and appears very clean inside and out-it has two small small fuel tubes on one side and the larger tank fuel line on the other. The top smaller tube runs to the primer while the lower one runs to the engine bottom and then from that area to the tank line where it T's into it as a return line(I presume).  Is there a check valve that's stuck?  Help

Answer
Hi Dave,

I'm kind of stumped at the moment.  Usually there IS a check valve at the vent hole or tube.  You may be right...A piece of dirt may have gotten lodged in the valve.  I would remove the lines as needed and use another piece of tubing to blow into each opening as a test.  Next, disassemble the carb, again as needed, to investigate further.

Let me know how you make out.
Michael