Hi guys,
I'm rebuilding a 2000 cbr600f4. I have accumulated piles of extra parts. Enough to keep it going for a while. I've run into something not in the manual. There are vertical numbers on the ciirclip cutout are such as "hf1" "hf3" then one horizontal letter such as "f" "e" "d". What in the world do these mean. I've never found a 4 out of 12 pistons so I dont think it indicated cylinder, only 1-3.
Now my last set of wiseco pistons had no such numbers, only long numbers on top of piston facing up.
what is this nonsense?
I understand crank codes and case codes to indicate bearings but what do these numbers mean? Help?

 

Same thing, but matched to bore finishes, etc.

Dink.1170