Vacuum leak

[JoBoy68]

83 GL 1100. I have been searching for a vacuum Leak, did the smoke machine and all I saw was smoke coming out of the throttle plate shafts , I dismissed it because it was all of them from all 4 carbs ,was like how could they all go bad at once and was thinking throttle plates are open when running , so I am wondering if this is my vacuum leak and if it is how hard to change . is it a complete carb tear down ?

[Rambozo]

I think Randaaks has the felt shaft seals. It's kinda a pain to change them as the throttle plate screws are staked in and really should be replaced, if you can get them. I've often had to make them on the lathe for various carbs.

Another method to find leaks is to use an unlit propane torch to spray propane around the running motor. A small diameter hose on the torch helps. Then listen for idle changes or watch an exhaust analyzer HC display to find the spot.