I have MS660 with stock muffler and while I love milling in general, the exhaust from that beast is just unbearable. I can't find a position just right so I don't have to breathe that stuff. On 660 port blows exhaust at the top of the bar which then bounces off the log and goes half up your nose and half down. Any recommendation for mods I can do to get exhaust fumes away? It would really make milling much more pleasant for me.