Husqvarna 435 mystery problem

[AmishKyle]

I bought a 455 in pieces straight gassed, long story short rebuilt everything and did the 60cc top end.. could not get to the thing to run good at all rebuilt carb twice finally bought now oem carb and it runs like it’s EFI.. never did find the culprit just accounted it to the ethanol gunked up small ports and unseen