Thanks Andy:

Supplementary question: Looking at the parts list on the TSO website, the Honda parts book lists part numbers for pistons designated as "B", "C" and "D". Barrel sizes and piston diameters were set out in a September 9, 2007 post from Matt at Tyga as follows:

Cyl A - 54.008~54.011
Cyl B - 54.004~54.008
Cyl C - 54.000~54.004

Pis B - 53.966~53.969
Pis "" - 53.962~53.965
Pis D - 53.958~53.961

I understand the unmarked piston goes with the "B" barrel. According to the post above, the "B" barrel is the middle size as is the unmarked piston. But does that mean that the piston referred to as "C" in the parts list (part number 13103-KV3-830) is the middle sized piston, or more importantly, the correct one for the "B" barrel? If it is unmarked, why would the parts list refer to it as "C"?

Interestingly, the same parts book refers to "A", "B" and "C" barrels, but they all have the same part number!

I have asked Leonard at TSO to clarify, maybe even examine the actual pistons for a mark, would appreciate your wisdom as well.

Thanks.