If your running kart bearings Glen and you wash your mowchine alot, you need to make sure to lube the bearings or they will rust.
I like the NTN free spin bearings and use the removable shields on them. Only have them on the SP as I got lazy on the last 2 builds, but you can remove the shield, clean it out and relube the bearing. I know APS carrys them. I just bough the cheep free spins for my FX build and used what came on the BP.
Paul