WHAT??????
A flywheel is a weight, rotating mass.
Quads and dirt bikes have them??????????? They have flywheels. Yes. Dirt bikes have manual clutches. quads have either manual clutches or CVT clutches.
What are you talking about? Where are you going to "road race" a mower?
How old are you?
I'm thinking you are talking about the CVT transmissions on the Quads. Those would be clutch weights, and no, mowers don't have them, unless you are a good clutch tuner!
Paul