I fly 28's and have never experienced or heard of this so it's interesting to know should it ever happen. However, I was wondering if there is any chance it could attributed to say a "Hot Spot" on a cyclinder head or timing problem? Afterall, Motor cars are known to do this. I had an old Cavalier that used to continue running even after I had locked it and walked away LOL!!!! God it was spooky.
Anyway, interesting comments made and noted in the other postings.......thanks Chaps & safe landings!
C.N.