My motorcycle has developed a low speed stumble that clears up above 3000 rpm.  Has gotten worse over the last 2 years.  Yearly use varies from  only 300 miles to 1,500 miles.  Strongly suspect the low speed circuit to be blocked by dirt or varnish.  Many (including local Honda service mgr) have expressed success in the past cleaning up stumbling carbs without rebuild using Yamaha "carburetor cleaner"  that consists of 2Butoxyethanol and Xylene (no longer sold) and filling carb thru fuel line, letting soak then draining from carb bowl drain plug.  Does Berryman have a product that is suitable for this?  I am concerned of causing damage to internal rubbers or plastic components and wish to use the correct cleaner.  After reading through your FAQ pages I am thinking of using your #2616 product Thanks!