Dragonflyspit - I used to rebuild those carbs for a living. I'd be happy to take a look at it for you if you're ever near Tucson.
One of the biggest problems I've seen on that particular carburetor are loose screws between the mid body and upper portion of the carb. When you spray cleaner down the carb, it allows air to enter the carb between the two sections because the old varnish was keeping it sealed. It's very easy to check to see if this is the problem. Remove the air cleaner and grab the top of the carb. Try to turn it left and right. If you notice any movement at all, you can pop off the carb and access the screws at the base to tighten it up.
Jim