Chinese Manufactured Carburettors

[Kevin]

Just before Christmas I acquired a Ryobi lawnmower fitted with a Suburu engine that is made in the PRC. The mower had been standing a while and on starting it I noticed it was hunting slightly so I decided to clean it in my sonic tank. Apart from the issue with the float bowl seal swelling so that it no longer fitted the job was easy and bound to bring good results! However on starting the engine after refitting the carb the hunting was much worse than before. In disgust I turned off the engine, folded-up the handlebars and put the mower in my shed. Fast forward 3 weeks and I decided to revisit the Ryobi and removed the carb. On closer inspection I noticed that there was red coloured staining from a Welch plug that is normally hidden from view by one of the carb mounting bolts. This looked like some type of sealant that had been reduced to a liquid state during the time spent in the sonic bath. I cleaned of the staining and painted around the Welch plug with nail-polish and reassembled. Once the revs stablised after priming/starting there was no more hunting.
I wonder if anyone else has had this issue with the Chinese made carbs fitted to the engines like the Rv150/Sv150 or similar engine?