Does not back fire. (it did when we first started having this problem, but it doesn't now) Screws are set to factory. (One is 3.5 out and the other is 1.5 out).Intake clamps have been checked and tightened. The pilots are, whatever comes with the LTE pipe kit (Note: we had this problem even before the pipe was installed). Floats have been adjusted and checked.
We have been through the carbs many times and we are wondering if it could be associated to the valves???, or some thing else. We agree that it seems to be an air leak of some kind, maybe. Are these carbs very sensitive or what? We want to eliminate other possibilities before purchasing new carbs, as the brilliant factory technicians suggest...