If Napa doesn't work for you, try your local motorcycle dealership that has a good parts department. My dealership here has all kinds of them (different sizes). The modern Japanese bike has a lot of copper washers in the brake and cooling systems. Definitely take one with you to match up the ID, but I've gotten many different copper washers from them over the years (I've been racing bikes for 11 years so I'm more familiar with how this dealership works as opposed to Napa).
Just another idea of where you could get them.
