Yes, burbling at full throttle. I just called advance auto and they said they cross referenced the plug number to an "autolite" plug and they are only $1.50, so i'll go get a couple of them and give it a try.

Another thing is I jsut changed my gas brand 5 flights ago, from motul to penzoil. Maybe that had something to do with the plug fouling. My mixture was pretty close to perfect for the whole life of the engine.