'96 K1100LT, 40,000 mi. New to me two weeks ago. This all happened on a 4,000 mile two week vacation. The symptoms: 1: Surging, cutting out. On the highway, it felt like riding into a light, gusty headwind. A puff of wind every few seconds; that's what I thought it was until I saw the grass and trees weren't moving. It was worst at speeds below 60; not so bad at 80, but always there. It would not respond to small throttle movements, but a mighty twist would make it lunge forward. The only conditions it would pull smoothly and regularly were close to wide open, and fully closed throttle. Around town on undulating 40 mph streets it was like riding a bucking bronco.
2: Erratic poor charging. Had to jump it several times from my friend's bike. Finally charging failed completely. Battery light had never come on. When I started paying attention to it, it was not coming on even with the ignition on, before starting.
You may not see any connection between these symptoms. I didn't,, and neither did the mechanic who fixed it. I had resigned myself to living with the poor running issue, but the charging failure had to be addressed. I took it to Mountain Motorrad in Flagstaff, Arizona. They dropped everything to come to the aid of a stranded traveler, starting with replacing the burned out battery bulb...only it looked good. Reconnecting the instrument pod, it still didn't light up on ignition. So, he started a close visual inspection of all the wiring he could see, and found The Answer within five minutes. The alternator rotor exciter wire was disconnected. It's a slide-on connector that goes onto a spade lug extending vertically from the back of the alternator, and the connector was just hanging beside the lug. Reconnected it, Bat light on, fired up, Bat light off, full 14.3V charge at the battery.
So, off we went, starting with some beautiful, twisty roads south to Sedona and Prescott. A few miles outside of town, I suddenly realized it was running better ... in fact it was running perfectly! Uphill, downhill, fast, slow, straight, curvy, it never hiccupped.
Knowing what the cure was, it all made perfect sense. The connector took quite a firm shove to get it on the spade lug, so it couldn't have just popped off by itself. It must have been taken off for service, and not put back on correctly, just left resting on top of the lug, held sort of in place by its own meager weight. It made contact well enough to charge the battery some of the time, and some not. Meanwhile, the engine's vibration was causing it to dance around atop the lug, throwing off tons of RFI and confusing the computer. Get a nice solid connection, and all is well. That was about 1500 miles into the trip, and for the remaining 2500 miles, it was a joy to ride.
Something to check... it's not easy to reach or see, but a good flashlight peering in under the coils from the left side will reveal it.
