Bi2 engine

[Fox]

I keep seeing references to a Bi2 engine that's supposed to be more powerful. The Vento site has it listed as a 2 stroke but I've seen ads for scooters for sale that say it's a 4 stroke.

Anyone know anything about it?

[90GTVert]

I just figured it was a gimmick. I've seen it advertised on Vento 2Ts and 4Ts. Probably does as much as that fancy Silvertone exhaust system Vento uses (generic muffler with a new badge).