avstar carburetor problem

[Moon Doggie]

After only fifteen total hours on my RV-7A(O-360 Aerosport power,Hartzell constant speed prop), I experienced a partial loss of power at around 1,000 FT on take off. I was able to return and land with the engine running rough. Power continued to degrade while taxiing to the ramp. Running rough, I could not get above about 900RPM. An A&P mechanic diagnosed the problem to be at the carburetor. It was discovered, after seperating the carburetor body, that the mixture boss attached to the bottom housing had rotated. This essentially produced the same effect as pulling the red knob. Neither Bart,at Aerosport Power, or the Avstar people had ever heard of this one. I went carbureted because they were bullet proof. Oh well, I guess I'm in that infant mortality zone. In hindsight, I think this problem had been progressing for while. Because, after installing the new carb, EGT's and CHT's were much cooler, especially EGT's. If EGT's are higher than normal, or you can't lean as much at cruise before you peak, it may be an ensuing indication of this problem. Due to this problem's critical nature, I wanted to get the word out.