Modern Buddy

were there any engine changes from 2007 to 2024? I just see a 07 engine on eBay. If I wanted to have a spare engine for what ever reason, would the 07 engine work?

Most likely. PGO's design uses established bits from Honda and Yamaha's parts bins and it works pretty well. If anything changed, I'd expect it would be the ancillaries and not the shortblock.

Yes, you can do silly things with them and make them pretty quick.

Having owned 2 Buddy 125's in the past and a current 2023 Buddy 125 I don't see any changes with the motor. Also, nothing different noted or updated in the paper service manual between those years. I also believe the steel wheels would easily mount up on a new alloy wheel equipped motor and vise versa without any issues.