exhaust pipe burned through

[Graham Singleton <100421.2123@compuserve.com>]

>>My understanding is that glass-based insulants should not be placed in
contact with stainless steel above 500C, otherwise the S/S is eroded.<<

I'm sure you are right, however , it's the mild steel pipes that are
burning through. In my experience, based on those wise few soles who have
EGT guages, 912s tend to run very high EGT. Typically above 850 deg C.
(1560 deg F)
Graham