Modern Vespa

Have to do 2 posts (can’t post more then one pic at a time)

This is what plug looked like after long fast ride on Thur.

3 days later - same plug after a shorter ride (no more then half throttle). What gives? Air leak?

An air leak is possible. It can also be throttle position differences, you have an idle jet, midrange mixer and main jet if your still running a SI carburetor. You also have the throttle slide which can have cut outs depending on the slide.

Without going into a lot of detail each jet affects mixture at a throttle position and can be additive.

Here's a quick intro to a few parts.

You can. Just hit “Add Attachment” after you’ve selected the first file, then you’ll see a new “Choose File” button to add the next image.

Sorry, should have specified -
Dellorto phbl 24mm. Strange to me that one day plug looked good, next ride looks lean.

I have a phbh on a scooter, you still have a few jets and a needle.

To me both pictures look as bad as each other. If it doesn't seize, then it is doing damage, kind of colour. Stop riding it. Assess the damage. Re jet completely.
Good news is, if the plug is that colour it will be really slow.