Weird Sputtering/Grinding at 80+mph -'00 1150GS
The longer I have this bike the more things I find wrong with it. I don't mind fixing them, but sometimes it gets expensive. The latest one I found yesterday cruising (read: "flying") down the highway. In E-gear (overdrive I think?), going up a slight hill at 80-85 I could hear a weird sound coming from the front half the bike - maybe underneath me. It sounded like a mix between an airplane sputtering about to stall and a metallic grinding. I didn't feel a lack of power during this. Confused I let off the throttle and the noise went away. I pulled harder on the throttle and it came back louder til I heard some sort of pop and I could have sworn I felt something fly past my left foot. The pop sounded like a cough and had a bump of power loss, and looking back I didn't see anything fly off the bike. Startled, I let off the throttle immediately. The bike continued to ride fine. Nervous, I didn't test it anymore. Today I was going down the same road and wanted to see if I could get it to do it again. And I got the same results, though I didn't pull hard enough to get the pop-cough. I got the sputtering/grinding and I stopped before it got worse.
My first thought was some sort of engine trouble, but now I'm thinking it's the transmission, since I've never heard it in any other gear and only does it under heavy load (80+mph). I also think maybe the thing flying past my foot with the gear shifter twitching with the transmission spazzing out. Has anyone else had similar problems or know what could cause something like this? What is likely wrong, and is my bike going to detonate anytime soon?