We bought a new lawn tractor. We also bought a new universal bagger attachment for it. We wanted to collect grass clippings for composting. But the bagger blew clippings and dust all over the operator's back. Bummer!
So I fixed it by installing a new foam gasket around the cover and gluing the rubber seal that connects the bagger to the mower deck. Problem solved!
If your lawn tractor bagger blows out as much dust and clippings as it collects, this approach may work for you too. It's inexpensive and easy to do.