i have had 2 OS 140 rx ..had to change bearings in both but used SKF W 6904 RS1 bearing ...its stainless and has last as said earlyer in the tread like 250 flights ..one of the original got destroyed after less than 10 flights ..i also change the top to the 3M 2 plugs top (you get it from http://www.f3alorenz.de/ ) and used Os f and Os 5 this helped a lot on the problem from midd range to full ( rich).
but mine has also stopp some time on ground just got soaked and stopped ...dont really know why but it has just been to start it again !?