[Mister Moo]

I see a little irregularity in the cake - no biggie, that. Smooth it out a little and make sure no unburned flakes are trapped in those chunks. Why are you suspecting this pipe is burned out?

A burnout is going to grossly enlarge the airhole where it enters the chamber, make a pretty obvious pit on the wall of the chamber, create a burn mark on the outside of the pipe and, maybe, tip itself off with a super-hotspot you feel while smoking the pipe before something else pops up.