When I got the used Emaxx I bought up and running, the slipper was no problem. I upgraded to S600 motors and began toasting slippers in about 8min run time. I was melting the center out of the spur. I was running all 12 pegs and rinnung it fully tight, no back off - was still melting them. Just too much for that stock slipper design.

I run RRP slipper set fully tight - no back off at all and a RRP metal spur. No more problems, even for two or three runs back to back (30min+ run time) as quickly as I can change batts out.