RE: OS AX 46 needs more power
use a cold plug as well, this is key to getting all the power out of it, and check and seal all movable services, you can replace your bearings with aftermarket bearings with a ABEC7 rating its a much looser fit
and is used by racers and nelson engines etc etc , they have polyamide bearing retainers or other low friction plastic..they are lighter than metal retainers as well. all os heli engine use plastic retainer bearings
with your prop drive installed and a prop torqued down to test crank endplay it should be free and spin easily, i prefer to have some endplay with prop installed. os engines often have tight wristpins out of the box, i lap pin bore until there is free rotation as well, jett engines use .003-.004 big end clearance, os engines stock are very tight, i use kratex rubber abrasive small wheels to polish rod end bores to achieve
this clearance.