Pressure test the carb as well, if you are equipt to do so. Like Harley said, take a look down at the intake skirt through the boot. 036 can have a bit more blowback than other models from Stihl. They have a teardrop intake port and the lower portion provides more intake duration than any other Stihl I have worked on besides possibly the 660. It sounds like you ponied up for a new OEM carb, but it still may be the issue. Some of the $20 AM carbs for this model are made on the very same assembly line as the OEM Zama are. In fact, up to about 2 years ago, they AM ones would come with Zama cast into the pump plate and the correct model number (?C3A) cast into the side of the body. Only the “Stihl” name on the metering plate was missing.