Kweasel, some academic questions if you don't mind.

Bear in mind the following questions apply only to simple 1 and 2 cylinder, air cooled, two stroke engines.

Question 1: Regarding that jet ski engine with the loose piston fit. Please explain and expand on that position.

Question 2: Why does an engine with a tighter piston tolerance require a longer break in and how does it benefit from same?

Question 3: What specific part of a piston requires a break in? Leave the ring out of it please since it's not part of the piston.

Question 4: What part of a piston is intended to make contact with the cylinder wall?

Question 5: How long (on average) does it take to break in a piston ring, and which is the harder material, the ring, the cylinder wall, or are they the same?

Question 6: What parts of an engine actually get broken in?

Question 7: What part of the engine benefits the most from the break in process?