Lots of PPL Will Say you will Over Heat it... But I call BullShit on that. And did it on Lots of my Bikes. (Yz490, Yz250's And Yz400 )
And the Shop i use to work at Puts it on 2 Strokes all the time.
I know A Lot of ppl that do this and i Love the Sound of a Big Bore Bike With Wrapping on the Full pipe