Arrived home from work tonight after 28 mile commute. Bike sat outside for a few minutes while I opened the garage and let the dogs out. When I went to push the bike into the garage I could hear a noise coming from the gas tank area. The noise sounded like a small motor running in the tank.
Popped the seat, removed the "brain" and disconnected the battery. The noise continued. I lightly touched the outside of the gas tank and I could feel a very slight vibration. Pushed the bike into the garage and the noise lasted for about 5 more minutes and went away.
Bike has 160K on the clock and the only thing I have been doing differently is adding Techron at each gas fill to clean injectors and hopefully cure some hesitation the bike experiences when accelerating through each gear.
Only guess I have is fuel flowing back into the tank to equalize some pressure difference.
This is probably unrelated, but on the last 5 miles of my commute home on Friday, the bike began to surge and lurch violently. I needed to maintain 7000 RPM in 2nd gear to maintain 30 MPH. Engine never quit, but extreme surging and lurching continued until I was about a block from home. Suddenly the surging and lurching stopped and the bike ran normally.
Only thing I can figure is that some foreign substance/object lodged in one of the injectors and it took about 5 miles of extreme surging and lurching to pass the obstruction through the injector.
Any help is appreciated as always.
'85K100RT; '90K75RT; '91K75RT; '05R1200GS