I have been flying mine with an OS 46FX and it does quite nice. Best thing is the fit inside the cowl. You need to grind some of the fins off the muffler for side clearance and open a hole about the size of a 50 cent piece to clear the front bottom of the muffler. Makes a very neat installation. My local group has 3 of these flying. I have 5 more for sale for $150 each.