Extreme flight chin yak os ax55 13x4 apc 10 gallons? never hit the earth. Noticed a diff noise. Felt little funny spinning over by hand. Ran fine though. Found that the top of the rod was seized to the wrist pin in the forward position.(Hard to get off crank pin) Soaked in tranny fluid to loosen. Disasembled all parts,cleaned ect. /////Works and sounds mint again. If I did not fix it, The wrist pin would have fore out piston. (Holes in piston that wrist pin rides)
but whatever
Just a FYI!