This is like cleaning and painting a clogged radiator. On OH-NAN! generators I used to use Berryman Chemtool. Dribbled it onto the throttle shaft and let motor vacuum suck it into the engine. Dissolved gum and varnish on the throttle shaft which made it less sticky for the governor to fight.
On carb rebuilds I sometimes had to soak disassembled carburetors overnight, rinse in boiling water, then use a rubber tip blow gun at 140PSI to force gunk from tiny passages. How any of that is supposed to happen with Mouse Milk alone is beyond me.
