Get rid of old Fuel residue ...

Sharpertek shellac buster, but it will take zinc dichromate, anodizing etc. off, about $80/gal. They say 7-10min soak max, but I had a rough Q-jet that took a couple hrs., the main jets were so corroded You couldn't read the size stamping any longer on one of them.
That was followed up by a few stints in the ultrasonic cleaning tank.