Toro GTS-150 / Briggs & Stratton Carburator difficulty

Yes the groove goes down inside the carb and the needle goes in and touches the flat side.......

There is an L-shaped molded rubber hose that goes on the the outboard fitting. It's a vent for the carb bowl and points straight down.

Shown in one of the photos is the crankcase vent line. There is a short hose connecting it to the back side of the air cleaner box.

This carburetor has been discontinued. Every other carburetor under the sun has a $9 ebay made-in-china replacement but not this one.

Here's a picture of that vent hose. Fuel line is removed.