I recently finished my first kit (Sig Mid-Star) and I put an OS .52 four stroke on it. This is my second plane, my first being the Avistar RTF with the OS .40 two stroke. I was taught that a good way to check the need valve adjustment was to pinch the fuel line at full throttle and the engine RPM should temporarily increase. I used this technique for the two stroke, but on the four stroke the engine always dies immediately. I can richen the fuel mixture just short of stalling the plane and it will still die when I pinch the fuel line. So my question is,

Does the pinch test work for four stroke engines?


Tom Pruitt