2001 Beta REV3 - Gearbox Oil "Porthole" issue

[Cameron J]

Hi,

The 'porthole' for the gearbox oil on my bike will not tighten properly.
Turn it anti-clockwise and it comes out, turn it clockwise and it screws in and then keeps turning without stopping.

There is minor weeping around the seal.

Q1: Is this normal?

Q2: Will I cause big damage if I keep riding it in this state?

Any help much appreciated.

Thanks
Cameron J