My Ltd had sat up for 7 yearsbefore I bought it. (I spent the last 3 of that 7 trying to talk my brother-in-law into selling her to me!).
On mine, so far, I've changed the fuel tank (rusted out),and the fuel pump to get her running. Like yours, she ran rough for about 2 tanks of hi-test gas & Gunk fuel injector cleaner and then it was like a switch was flipped and she smoothed out and also picked up about 800 more rpm's when idleing. If the bike would've had carbs, I probably would still be working on them.
As far as gas mileage, mine will pop 50 mpg @ 65mph on the interstate and I've talked to some guys here in Marion that I've rode with that own 1500's or 1800's and they say the best they get is about 35!
My thinking is the more you ride thatbike the more you'llwanna keep it!!
One other thing, when i first got the bike she was extremely dusty/dirty & I was gonna take it to the car wash to clean her up. MyIn-lawsvery quickly in formed me not to do that and that soap and waterhad never been used on the bike.
What did they use?? A soft rag, Lemon Pledgeand Mothers chrome polish!!
Believe me,, the Lemon Pledge works like a champ, from the windshield, to the paint, and definitly on the leather!! Removes bugs and all!
Interest has been sparked! Let's talk when you get closer to selling. That is if you can force yourself to part with it. I have a mint '85 that is ridden daily just to satisfy my love of getting on it. I was, however, not satisfied with the E3s and went back to the E2s. It seemed that I broke the rear tire loose too easily when accelerating. Some front end slide when cornering hard as well. My voltage went from the 13.8 you mentioned to 14.5 after completing the soldering in place of connectors. If you want to keep the connectors, perhaps ensure the fittings are all lubed up at the stator, rectifier and starter relays. Just a thought. Personally, I have used both sea foam and Techtron in different bikes. After a round of Techtron about 2000 miles ago, I went to Lucas instead recently. (I use it in an old truck with great results.) The difference between Techtron and Lucas was extremely noticeable in my GL. Hence, the E3 rear tire change back to E2. As others have said, this 1200 Ltd will knock the 1500s off regularly in performance. Enough rambling.