I use a 1/8" male pipe thread x 1/8" compression tube brass fitting. I drill and tap the muffler for 1/8" pipe thread, and screw the fitting in with a dab of JB Weld on it. Then I silver braze the end of a piece of 1/8" copper tubing shut on one end. Drill some tiny holes in one side of the last 1/2" inch of so of the tubing. (Like .040" holes more or less.) Insert the tubing into the compression fitting, so that the end of the tubing with the holes is right in front of the exhaust port, with the little exit holes pointing away from the port itself. Tighten up the fitting. Attach rubber hose to the other end of the tubing, running to your smoke pump setup. Works great, and you can remove the tubing to clean/check the spray holes if needed....

Hey, I just noticed that I am going to hit 4000 posts pretty soon. Do I get a prize???

AV8TOR