I believe these are the same as what's used in the X-5 slipper.
(I'm not too up on Losi parts)
http://www.losi.com/Products/Feature...rodId=LOSA9942
Before I've replaced that bearing spacer on my X-5 with shims, to make the layshaft as free running as possible & allows slight movement so that belt runs in the centre of the pulley gear.
MiCk B. :-)