Clean the tire and rim beads, then clean the tire bead. I use the cheap brake cleaner from Wal-Mart. Then before you mount the tire on the rim, clean the tire bead. Basically, clean the tire bead really, really well.
AE FT B44.2, SC10, T4, B4.2, B4, 18T, 18R, TC4, L3.5O ** Losi MRC Pro ** CRC Carpet Knife ** Axial XR10, AX10, SCX10 ** Traxxas EMaxx ** JR Z1