Carb problem, surging after ultra sonic, enlarge holes behind Welch?
I have a Tecumseh 8hp on a 15 yr old snowblower that was given to me. The carb has a fixed plug on the bottom holding the fuel bowl on and a low speed adjustment on the side. When I got it, the engine was surging badly that it was unusable. I cleaned it in my new ultrasonic cleaner for 60 minutes using the manufacturers recommended $65/gal Carburetor Shellac and Varnish Buster, the side Welch plug was removed, after cleaning then a dunk in a water bath then immediately every hole was cleaned using a welder's tip cleaner. New Welch plug, sealed with nail polish, let dry for a day, reinstalled and no difference with the surging.
I The did it again, removed the carb, disassembled, Welch plug removed, in my ultrasonic cleaner a second time using Berryman's Carburetor Cleaner dunk tank as the solution, removed after 30 minutes? 60 minutes? I forget which. cleaned every hole using the tip cleaner, then I cleaned every hole using wire gauge drill bits, then new Welch plug, sealed, next day installed, still surging, No difference.
I was thinking of doing the ultrasonic cleaner again for 30 minutes, then spraying carb cleaner in every hole, then tip cleaner, then wire gauge drill bits. Then should I install it? Or should I enlarge each hole behind the Welch plug using the next size larger wire gauge drill bit? Would enlarging these holes help with the surging?
I don't want to give up and install a Chinese carburetor. I want to learn what is necessary to solve the problem for my future knowledge.
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