Modern Vespa

I just changed the belts and rollers and put in a new malossi double red sponge, the belt cover is now installed but the air box won't screw into place and when I start the scooter it's really loud and smells like petrol so I think it's getting too much air, because the box isn't mounted property.

Basically I put the screws into the holes and tighten them, when they are fully in they just pull out of the holes without any force at all

Does it need to line up or cluck into something

How can I fix this?

You need to line up the air box on top of the transmission. There should be a couple notches for the bottom two screws and the top screw I think lines up with the mud guard. I hope that helps.

A bit late now, as you'll need some remedial work, but the way to insert screws back into plastic is to introduce them to the hole, then gently turn them anticlockwise until you feel a 'notch'. Then you've found the start of the original thread and the screw will tighten down without stripping any more plastic.

As you've now stripped the threads, I would experiment with just one hole with a slightly larger diameter screw *designed for plastic* like the originals.

Got it earlier thanks, just wasn't lined up no threads were stripped thankfully

Good that was a close call. 👍