I have a leaf blower homelite model ut08512a which is the fuel inlet on carb the one on the botton where the screen is or the one on the metering block

The one that comes from the fuel tank would be the inlet line.

Screen is line to carb.. Other is return line.

Return line? On a leaf blower? Really? When did they start doing that?

Mine has 2. PIA when they leak.

That's crazy. I had no idea they had become this "advanced".

Stopped at HD today, every gas blower has 2 fuel lines.

I'm still living in the past... lol

Hi,
Return lines were mandated a number of years ago by the EPA to reduce VHCs (or Volatile HydroCarbons) that can also be considered as emissions even though not burned.
The true answer is the one with the filter on it so that trash is not picked up in the tank.
Peace,
Clarke