just looked at the pic I posted of my crank. In real life you can just barely see light between the crank and muffler (read rubber blow bag, snork). Has to be less then a MM. Might drill the hole bigger in the blow bag just to see if it makes a difference. They cost $6.99 at Harbor freight. $20 @ home depot. Is the same dang thing.
Think I posted it but the drain cleaning "blow bag" was put on as a joke. I thought it would expand and explode. Dang thing works awesome. I tested it against a Ace hardware small engine muffler and works better. I used a garden hose splitter and had both on at the same time so I could experiment. Silly blow bag out performed the "real" muffler. But the real one did sound meaner. Some vids and pics http://motorbicycling.com/f37/rivers...ild-23871.html