Well I added some dry gas thinking possibly moisture in the gas, no luck. Below is the picture of one of the plugs, they look fine. No matter where I set the timing 0*-5*-10*- 20* it runs best around 10* but I still am getting the back fire under load. Could the carb be bad from sitting 2 months dry? I know AJ is saying clean it, does that mean rebuild it? \ \
View attachment 1715113456
