Does lawn mowers need a muffler?

Well i have a craftsman 22HP riding mower, and i took the muffler off but left the pipes on just to see what it would sound like, and it popped a little but its not going to hurt it.

I actually got better gas mileage and it ran a little better.

Basically its like Straight piping a Truck, the motor is just alot smaller.

So it's fine