A while back I posted that my 1997 GL1500SE engine was stalling when I went up a long, steep grade and the motor was under stress. The bike ran great the rest of the time. Many of you gave me good suggestions on where to look. I finally found a grade about an hour from home where I could recreate the scenario and the engine would stall. I replaced the fuel filter and fiddled with the gas cap and there was no positive effect. I finally bypassed the auto fuel shutoff valve and the bike ran great without stalling. I purchased a MightyVac vacuum gauge and hooked it up to the auto shutoff valve as shown in the repair manual. I could not get a vacuum to show on the gauge. I removed the valve and disassembled it and found a large rip in the outer perimeter of the diaphram. I have searched all over for a rebuild kit, but they are obviously a discontinued item and unavailable. I don't want to spend the $125 for a new valve and will continue to ride with it bypassed. It seems that my only risk is if I leave the key on and fuel pump energized it could flood the bike if the carb float seats don't hold. The chance that a siphon effect from the fuel tank through the carbs seems very unlikely. I wanted to thank everyone for their suggestions and for helping me diagnos this problem.