I think it is called a crank bell, very new to R/C, but reading 3-4 hours a day. Anyway, the bell on the crank, with the gear. It is bluing, is it supposed to get that hot?
Clutch bells certainly will get very hot but if it's turning blue that is a sign that your clutch is slipping too much... which creates a lot of heat... which makes the clutch slip more. You can see where this is going.