It's funny how crappy the mileage is on the 605. I've had several Husky 610s with the same carb, and way more power, and they get at least 10 MPG better. 95% of my riding is off road though.
Kieth at ADB was talking a while ago about producing some new tanks for the +'95 models, he has access to the molds. Would be nice if they could give it more capacity, maybe by eliminating the right side cut out?