Is the the diaphragm that you replace behind the cover at 55seconds on the video? That is the vacuum shut off for the fuel. Not an overfill do hickey. If that is what you changed then you would have had to have turned off the petcock so gas did not run out when you removed the hose. Unless of course the tank was empty or petcock plugged. Pull that hose with petcock off then turn it on using a catch can of sort and see if gas comes out. If yes your good. If no your problem is between the hose and the tank cavity. See the hose on the other side off the one you pulled off at 140? That should also be the fuel out to the carbs. Pull it off and stick a rag under it or better yet a piece of hose going to a catch can. Reinstall first hose. Turn on the petcock. No gas should be coming out of the do hickey. If yes...do hickey problem. The other small hose on the so called over fill do hickey is a vacuum hose. Pull it off the carb,inspect and make sure it is in good condition. With it attached to the do hickey.....suck hard on the other end. Gas should now be flowing into catch can. If yes...good. If no...do hickey problem. All this is nothing but a shot in the dark diagnosis. It took me longer to type this than it would have to perform the actual test. Also what IP said to check.