I have a brand new piston with rings that I got when I bought a CRF450R 2012.
It has a mark HF3 on the downside. On the old piston there is marked HF2.
I have tried to google but cannot find any reliable answers, (I found that the same marking can also be used on pistons for cars).
Can anyone explain what this marking tells?
See also picture of the marking attached
Many thanks in advance