Are you sure yours spins at 2000-3000 rpm! That doesnt sound right to me. I'd back off that pump of yours if I were you.
The ones I've seen spin real slow. I see these in action regularly and they are a lot less dangerous to the operator than say, a flail mower. The saw blade only rotates at about 40-60 rpm and only produces saw dust which falls down along with the branches it cuts. Where as a flail mower has high rpm and flings stuff far greater distances. A lot of the farmers around me use these to great effect.
They just looks dangerous. Obviously no one goes near the blade when it spinning and the operator is 6-8 ft from it in the seat.
That big circular blade makes a helluva ringing noise as it cuts through the branches...
heres a big one with 4 blades mounted on a long extending arm.