I tried the APC 12.25x3.75 today, and a Tower .46 muffler. Pretty sweet. Forgot to tach it...next time. Even though the Irvine can swing a bigger prop, for an airplane that weighs in at almost 5.5 pounds I found that you really need mucho thrust. This prop/muffler combo is about as good as I've tried on my 53. It sounds more like a dirt bike than an airplane engine. Very pipey sound, but cool. If I had it to do over again, I'd go with a light 60 or a light 70-100 4-stroke, and put the rudder servo in the tail. I still might put the YS 63 on to break it in.

I had a scary thing happen. While cleaning up, I noticed that one of the SIG easy hinges on each elevator on the inner end was broken. I've been using them for 20 years and have never personally had that happen. Must have been the half throttle blenders today!