Cracked rear iron... I think

[Rotary Evolution]

must have found an older thread, i've got a stack of cracked FC rear irons and even 20B irons with the old thin castings that cracked.

is this Junito?

if it is the iron did you feel any hesitations? it takes quite a bit more work to break the pinned engines but it is still possible. on the stock pins you can crack one without even feeling a hesitation.