It is quite unusual for them to exude fuel from the carb, if somebody has removed the carb at some time it is possible they have re connected the fuel hoses incorrectly, it is important to remember that the fuel bubble is a purge not a primer, so it pulls full from the carb into the bulb and back to tank, if the hoses are incorrectly assembled you can push fuel into the carb, this would cause fuel to exude from the carb.
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It is quite unusual for them to exude fuel from the carb, if somebody has removed the carb at some time it is possible they have re connected the fuel hoses incorrectly, it is important to remember that the fuel bubble is a purge not a primer, so it pulls full from the carb into the bulb and back to tank, if the hoses are incorrectly assembled you can push fuel into the carb, this would cause fuel to exude from the carb.