My 'new to me', 89' Gl 1500 groans after being parked. I unscrewed the gas cap, and heard a "Poof" sound. After that, it no longer groaned, till after the next ride. (I have a 265 lb. Hannigan sidecar attched.) I'm only getting about 22 mpg. Any suggestions on what might be the problem ? When I bought the bike it only had 26k mi, so I had all of the fluids changed, new belt, 4 degree trigger wheel installed, I asked for tune-up, and carb adjustment, but was told the bike didn't need it. Otherwise it runs like a sewing machine. Thanks in advance.
:sadguy: