RE: os 46 fx
The O.S. .46 FX is a terrific engine that is powerful, reliable, and easy to tune. The .46 FX was notorious for "peeling liner" problems when first introduced, but if you're buying a good running example of the model, you have little to worry about.
I have one .46 FX and one .46 FXi engine in my collection, and both have proven to be very reliable and very user friendly over the years.