I'm just getting around to looking at the piston that had been removed from my 68 CT90, trying to figure out if it's std or over, and I see CS90 on the side then a 2 across from it. The other side of the piston just says Honda. Is it possible that this is not a ct piston, and is there a difference that will mess me up? I looked through quite a few posts, but I'm not seeing this issue. The cylinder looks not too bad, so I was hoping to give it a quick hone and go with a standard piston. (That may be a bad idea, not sure) Anybody have some advice or thoughts on this issue? BTW I still don't see std or any indications of oversize on it.