If you look close it looks like a small Phillips head screw got in there.
Some really great news though. It WAS recently rebuilt.
It has a dome top piston. Cannot find a maker name but there are serial numbers.
Almost zero carbon build up. The inside of the piston is sparkling.
The bore is 66mm and i can still see some faint cross hatch marks from honing toward the bottom.
This is great news for me. I have another 200es to overhaul and this saves me a lot of money.
I just need to track down a 200r cam. Lol!
I'll use the ES head so i guess i will just tuck this head away for another day.
It also has a copper head gasket. Im half tempted to reuse it. I won't but im tempted.
I was born and raised on Venus & I may be here a while.....