Chainsaw Repair

There is the possibility that this stuff was introduced at the original repair shop or plated out when the saw sat at My neighbors place for who knows how long.
The tank has shown  no signs of this orange residue since a triple flush and refill.

I am still having issues with it getting past 1/4 throttle, the main jet does not seem to be pulling & atomizing fuel.

Saw has new: Impulse pipe, Intake boot, fuel filter & line, carburetor ultrasonic cleaning and reassembly.
Original vacuum & pressure test led me towards the impulse pipe.


Could the carb butterfly penetrations leak enough to cause a loss of vacuum? I hate to spend much more time & money on this saw - he has 2 others that he never uses anyways
guy buys wood for an outdoor fireplace with 8 acres full of trees that need cleaned up