
Keep in mind, these tiny holes are so small, that testing it by putting water in the bowl didn't help. When you clean out carb, you're actually making the problem worse by making the hole bigger. So, the moral of this long story is - if your snow thower, lawn mower, or other Tecumseh powered machine is leaking fuel, especially after doing a simple carb rebuild, it may be a similar problem. Apparently time, vibration, and corrosion from the toxic mess they call gasoline now had thinned the metal bowl so much that these tiny pin-holes - too small be seen without help - could form. When placed up against the gas inlet, the latter is great for sucking the last l'il bit of varnish out of those pinholes. Inspired by frustration, I cleaned out the bowl again and took it into a dark closet where I shone a very small but very bright LED flashlight into the bowl - and discovered a couple of tiny pin-hole leaks right at the curve near the middle of the fuel bowl. Just spent 3 hours cleaning the carb with acetone, ether and even a vacuum cleaner.

Under the air pressure from the primer bulb, I saw a very thin stream of fuel shooting out the bottom of the fuel bowl - right near the nut, but not actually from there.
