Scooterotica

In the first pic, the odd shaped long port, square at the bottom and rounded at the top, perpendicular and just to the right and below the intake, is not connected to any transfer. I've probed the inside edges of it. It also corresponds to the location of the small rectangular port on the piston, just above and to the left of the wrist pin in the second pic.

I hate to sound so daft, but I can't figure this out. Anyone care to explain this?

Thanks for any insight.

It works as a boost port. Fresh charge pushed up from the crankcase below and through the piston into the business area.

At the same time aiding little end cooling!

Thanks, I thought it might be some scavenger port, collecting un-burnt fuel/gasses but couldn't figure how it would re-cycle.