Hi Glazer,
There is some decent temporary help. Get some stainless steel scrub buds (like brillo pads, but not like steel wool). Maybe copper ones will work too, but they are both cheap. You can get 6 at WalMart for a couple bucks.
Shove 3 into each pipe and secure with something like a spring hose clamp that will fit inside your pipes. The scrub buds will blow to the rear of your pipes under hard acceleration, but keeping the trottle moderate they should stay in place. When you aren't in the city, run a small rod up your pipe with a slight hook on the end to slide them out. I have two in each of my pipes to tone them down a little and provide a little back pressure.
Ride Safe,
Dennis
