How to remove clogging in aircraft fuel nozzles? I have a dual orfice fuel nozzle (Used in CFM56 Engine/ Parker make). The secondary orifice is not opening up even at the required injection pressure. It had been not used for 3 years and I assume that it is clogged. Please suggest a method to clean this.
Hoppes No. 9 is often used for cleaning aircraft fuel injection nozzles in general. This solvent is widely available for cleaning firearms. The cleaning procedure typically involves submerging the detached nozzles in the solvent for as long as necessary, typically 10-60 minutes depending on the level of fouling.

Disclaimer: I don't have any specific maintenance data on your nozzles, so you may want be wary of the applicability of the information I offer.