ok ive got a lovely varnished up carby here to try,its off that sach bike of my mates im gonna get fired up we hope then piss it off (which means sell it here),i dont expect the machine to get all this off so a quick spray blast with cleaner,a quick tooth brush scrub and compressed air blow through and into the machine,ive let it go 30 minutes looks better and just doing another 30,im using hot tap water and a ph neutral truck wash we have here called ct18,i still like soaking brass in vinegar though,it comes out so clean.