Echo gt 200r poor running.

Hello new here, I am completey stumped. I'm an intermediate small engine fixer… I've tried everything in the book. Engine starts, runs for a second and dies when it does run for 30 seconds it bogs. What I've tried

multiple New carbs, all new lines and fikter, fresh 91 ethanol free premix with echo red armor 50:1, spark plugs (old one was not fouled). Cleaned exhaust port and muffler. Loosens gas cap. Fuel lines are correctly routed. Checked and tightend head bolts. Checked carb mounts for air leaked. New carb gaskets, messed with the hidden mixture screw. Pulled head and inspected piston and rings. Checked magneto. Checked ignition and spark/ kill switch grounding (no issues) pulled fuel filter off and attempt to run without.

At this point I figure it's old age (8 years or so). I pour gas down cyclnder and start and runs no problem. It's 99% has to be a fuel issue. It's stumping me as I've pur multiple brand new carbs on. At this point it's headed to the scrap pile but cash is short and I need this to run. Any seasoned small engine mechanics have a list ditch effort??