I have a Brison 2.4 and I have a question concerning the mix settings. When I fly at half throttle, the engine sounds like it is 4 stroking. It doesn't die, just sounds funny. I don't want to take the chance of making things worse. It idles great and I get about 7400rpm with an APC 20/10. I will fly this way forever but if I may have a potential issue, I would like to address it now.