Manifold Vacuum Experiment

Aight den. Yall know good and dang well I caint leave well enough alone. I yanked the carburetor back off. I think I need wing nuts to hold it on now. lol I took the check valve out and inspected it with my magnifying glass. It had a VERY, VERY sharp square edge on one side. So, I took it and shortened it about 1/8" or so on the grinder and then took a file and put a really good bevel on it all the way around. I shortened it because I've read in some instances, the nozzle screw limits the check valve's travel. In any event, I believe I struck gold. Now it has zero stumble. I mean zero. We'll drive it tomorrow and I'll be able to tell more long term then. Thanks for all the ideas. They definitely helped point me in the right direction. All that said, this carburetor has had this issue since new. So much for real quality these days. lol