The spray carb cleaner stuff is not very effective for really gunked up carbs. The small passageways may not get sufficiently clean. It is better to "soak" the carb parts in a carb soaking cleaner. See the attached pic as an example of a carb soaking cleaner. You can use the spray carb cleaner stuff after soaking the carb parts to rinse and blow out the passageways before reassembling the carbs. Just my opinion...
Where can you pick up that gallon carb cleaner set up?