Small Engines (Lawn Mowers, etc.): MTD Yardman String Trimmer, small engine mechanic, tank fuel

Question
Hi Eric!  I am a Small engine Mechanic, I was brought a Model Y765 MTD Yardman String Trimmer, that has been left all winter with Fuel in the Tank. I know that You know what that is. I cleaned everything, Tank, Fuel Filter in the Tank, disassembled and cleaned the Mini Carb,relaced the clear plastic fuel lines.
re-assembled it, and it started fine with the Choke on but would only run about 5 to 6 seconds with the choke off. I rechecked everything, checked fuel flow to the Carb. Still the same problem.
It was obvious that it was lack of fuel to the Intake on Run.
I called a Tech at MTD, and he said I had to get a New Carb Repair Kit and Pull the Welch Plug and Clean out that passage, as it fed Fuel to the Intake. Well I Just ordered a new Carb and installed it and I still have the same problem. Do you have any suggestions for me?  Thanks Eric for taking my question! William

Answer
What is the engine compression?  Is there an intake or seal leaking from the carburetor mount assembly?

Is the carburetor gasket the correct gasket?  I once had a Echo where someone installed a gasket that had a smaller hole than the carb throat.  Would never idle...took me forever to fix until one night I just happened to see the problem.

Eric