RE: OS 46 FX rattle noise
UandA:
Strange as it seems, it is possible to have detonation at part throttle and not at full. Just for a test, try a 10x6 prop in place of your 10x7 and see if it changes. If it improves, the 10x6 is well withing the acceptable range of props for the engine, just leave it on or go to an 11x5 and try that.
Bill.