I dropped off my father-in-law's 1300 for the first service that includes a valve-adjustment. I hadn't run the bike for a few weeks, and it was running rough. I had to use 1/2 choke for the 7 mile trip to get it there or else it would stall.
Dealer had the bike for a week (I was away.) When I picked the bike up, they said everything was checked and adjusted and that there were no problems.
I left the dealer, but turned around at the next light to go back. The bike still didn't run right. They were closing, but kicked the idle up and said the bike hadn't warmed up yet. I drove it home, still feeling like the bike wasn't running like it did in the fall when it was new (1k miles ago.)
It sat in the garage for a week and I took it out today. At a light, I heard a plastic grinding/vibration and thought it might be the famous headlight rattle. Bike still wasn't running properly. At this point I'm thinking bad ground, loose cables, or carb is clogged.
I pulled into my driveway and the vibration started again. I got off the bike and looked at the source:
One of the plug wires was completely disconnected and the radiator fan was grinding against it as it hung down along the frame!
The only explanation I can think of is that the wire was initially loose, but still under the cover. The mechanic must have pulled the side cover off, allowed the wire to drop, and then didn't reconnect it AT ALL before he put the cover back on.
I pulled everything apart, plugged it back in, and the bike runs like new. Good thing I spent $200
