Carbhub Carburetor Replacement for Walbro LMT 5-4993 with Mounting Gasket Filter 799728 498027 499161 498231 494502 494392 495706 498134 496592 699318 699737 699856 699896 Carb

I had one that did similar and the carb needle was getting stuck and allowing to much fuel into the engine. If i had to guess, thats probably a Nikki carb on it, absolute fuckin nightmare to mess with in my experience. Order a new carb, walbro style and see if that corrects the running and smoking issue. Its also possible that the head gasket has failed, common issue on these single cylinder brigs, but I would expect the smoke to be more consistent.