I tryed to open a new forum but will add to this one
End the pass 2 years I have drop the exhust valve seat and 1 intake valve seat in 4 different 140 sport engines all have been the next day after engine cools down.
I use morgan 30% heli RPM 8300 to 8500 prop is a 16/11 valve setting is .002 engine Idles about 2300 to 2400 the last one I check temp on engine and it was 160deg.
Temp out side was appox 94 deg had no problems during flight landed . went home the next day went to start engine and locked up valve seat drop on to piston.I'm just glad Buddy Brammer had a spare to fly in contest any help in this sure would be welcome are any questions.