There is a jet down the center and holes that go across it. Clean both passages with a bristle from a wire brush.
If you take the air cleaner off completely, there are two 1/8" holes and a 1/16 hole on the face. Try to clear the left 1/8" hole with a bristle from a wire brush. It looks like a 1/8" brass welch plug about 1/8" recessed. That hole needs to be clear. You might be able to get to it just by removing the air filter and top cover.
Easier to check with the carb removed: Check the intake tube for being loose. They are known to crack and/separate from the mounting plate. With carb removed, it should not wiggle freely.