Interesting thread. I have a 3W106 that runs perfectly .. but a 3W80XI single that has all the problems listed in this thread. I have been pursuing troubleshooting method around air leaks using the red locktite stuff that AI recommends .. and have also noted a lot of carb blowback .. that piqued my interest .. is that connected to the air leak or something else? I was thinking it was an indication of improper functioning of the reed valves...

Dave