Doing some test with various diffrent props and mufflers recently I noticed throught the exhaust port of my G20 a very small vertical scratch at the bottom of the piston skirt. It is about half the dia of a modelling pin and about 1/4" long and possibly a thou or so deep and is visible when the piston is at BDC at the bottom left hand side of the picture, see the attached picture. Though the engine has several gallons of fuel through it the machining marks on both the piston and the cylinder are still quite visible. Should I be concerned about this or not.

Karol