Modern Vespa

Vespa PX200 - got an issue with gear getting stuck in 2nd when changing from 2nd to 3rd. No real problems with movement through the rest of the gears.

If I'm going slow and it sticks it usually helps if I rev it a bit when moving from 2nd to 3rd, but if I'm already going a bit faster then it feels like it's jammed in 2nd.

I've replaced clutch and gear cables, still happening.

Any thoughts as to what the problem might be?

The gears aren't engaging with the cruciform properly.

Either the shift cables are loose
Or the gear stack is worn and needs re-shimming…

Start with the cables and see if it improves things. I usually wheel the scooter back and forward (without the engine on…) to see how the shift paw is acting… adjust the cables accordingly…

If that doesn't work, it's a split of the engine and re-shim or driveshaft rebuild.