After about 1-1/2 gallons through my 25fx running like a champ the whole time, suddenly the motor seemed to lock at the top of the compression stroke, sent it in to hobby services to be looked at, I had it back in a week(thanks), they said they couldn't find anything wrong with it and that it was normal for ABC engines to be very tight(although it wasn't like this before). Well due to bad weather I finally just got out today and now it is still tight and now when I move the prop back and forth(not going through the compression) just moving it back and forth you can loudly hear a metal on metal scraping sound and can "feel it". I started the engine, it doesn't have near the power it had before and when I idle back I can hear the metal on metal sound...any ideas?

thanks
Bill