Engine Clanking -WTF!!!

[Goat Blower]

If the cylinder walls don't have any major scoring that your fingernail would catch on, you can rehone it and drop a new piston in there. It really depends on the condition of the cylinder wall. Being that the piston has an actual hole in it, metal fragments are most likely in your pan. If that's the case, than you might be able to get away with honing that cylinder, but if any metal got through the pickup screen and filter and into your bearings, a full rebuild might be best because you'd have to pull the motor anyways. I'll try and find a minute to get up there. Keep me informed on what you find.