Ultrasonic carb cleaning problems

[Steve_P]

I worked in small engine shops for 6 yrs. Anyone that thinks you're gonna clean a snowblower carb that sat with 2+ year old gas in it with a few shots of spray carb cleaner is delusional. This was in the 1980s and we had the toxic Zep agitating carb tank and sometimes even that didnt work and we had to install a new carb. For something that just needs a rebuild, sure, carb cleaner. If it's coated in brown varnish, no