I just ran the engine again, with a little different setup. This time one stack was plugged, and the other one was wide open. I might add that the end of the open stack had to be cut off to allow the cowling to be installed. I then added an extension of about 3", but did not reduce the diameter. The 16-10 prop seemed very promissing, but when I switched to the 16-8, I was even more impressed. This engine runs like an OS 46FX. It will idle all day long and accept full throttle at any time. Unfortunately, my tach battery is dead, so I don't have any real numbers to share. It sounded best with the one stack open, and performed perfectly on the 16-8. Nose up tests didn't provide me with any surprises. Still running 10% powermaster. There is a video on here somewhere showing STG doing engine tests on his 160FX on a pipe, with instant accelleration. My engine performed exactly the same as what you see in his video. Only difference being the prop size. I don't know how I could ask for anything more out of such an affordable engine. Regardless of price, this thing is now perfect.