It must be the carb. You have covered everything else.
I would do a carb rebuild and do a carb cleaning using a dip solution. Dipping the carb cleans much better than spray cleaners. I use Solder Seal Gunks "Hydroseal II".....a fantastic cleaner.
I would do a carb rebuild and do a carb cleaning using a dip solution. Dipping the carb cleans much better than spray cleaners. I use Solder Seal Gunks "Hydroseal II".....a fantastic cleaner.