Well, looks like you found the problem. Fuel pressure should hold 57-60 even at wide open throttle and not drop like a stone when the key is turned off or when the pump stops on the initial key on prime. Heavy bubbling like that as well as a rapid pressure loss points to a leaking fuel line. Some have made repairs to the unit with submersible fuel hose. Just use the correct fuel injection clamps. Obviously first thing is to pull the unit and decide repair or replace. You will need to make a fuel flange tool to remove the cap. Plenty of home brew ideas on that in the search function of the forum . No point in driving the bike in it's current very lean condition. Good luck and keep us in the loop on the progress. Here's what it looks like inside and the common issue with them. Unless it's obvious, you can pressure test the high pressure side by pulling the corrugated hose (purple) off the pump and capping it. Add pressure to the fitting end and look for the leak.Sorry I am an idiot...fuel pump sender connection Located under the gas tank cover. Duh...So I connected my fuel pressure gauge and here’s what happens when I turn on the “run” switch the pressure shoots up immediately to 55/60. Yeah at idle drops down to 45. As soon as I switch off the bike it drops down immediately to zero.