can you run bigger that mopeders do yes. but a bike that changes gear ratio's ,either gears or cvt, can have a shorter more powerful power band that flows more fuel but for a shorter rpm range. so for instance a motorbike can push out 10 hp and cover 4k rpm with it's power band but a moped has to cover all of the rpms after the clutch engages. sorry those numbers are pulled out of my ass.
why i don't like big carbs.
hard to tune , worse mpg, and not a huge gain for money.
if it's a race setup those negatives are obsolete.