I got my SK 50 on Wednesday and broke it in on the test stand yesterday. I followed the instructions to a "T". Talk about pinch. This is a tight engine, much tighter than my 46ax was out of the box. Well it idles down nice and transitions without a hiccup. I have thrown it in my old nexstar ( the 46ax went into my midwest aerobat ) and will be going to the field this afternoon to give it a shakedown, unless it rains. I will let you all know how she does. I think we have a great $60.00 motor to play with.