You could use a cheap can of brake cleaner ,Boston 300g Aerosol Brake Cleaner $7.50 ,you may need to drill the cleaner nozzle and push in the small plastic tube from a WD40 can , then spray that into all the orifices to make sure they are clean.
Sometimes I need to use fuse wire to clean a jet back to original size and sometimes you need to push an oxy tip cleaner through if a pilot jet etc won't unblock after cleaning.
I have heard some people say the only thing after cleaning the carby that stopped the surging was to increase the jet size.
Most of the time the surging is the blocked jet on top (pilot jet)
I've been meaning to try Acetone overnight but as we know What NOT to Soak
Rubber parts (gaskets, O-rings, seals) – acetone will swell, crack, or dissolve them.
Plastic pieces (floats, choke housings, etc.) – may soften or melt.
