1986 Honda Shadow VT700C electric problems?

1986 Honda Shadow VT700C electric problems? - 1
Added (1). I bought this bike about a month ago, and right off there was trouble with the turn signals. Fixed it, no problem. It runs rough. It used to run ok, but now it just won't start. I think the spark plugs aren't hitting it off right, and it has 4 of them. So, that points to the ignition coils, black box and/or battery, I think. Another note, the tachometer sometimes goes insane. Turn the key, and it jumps up to 8 grand, bike not started. The tach is connected to one of the coils. Possible lead?
Added (2). More goodies:
Bike has 80,000+ miles on it. Carbs were redone, but doesn't entirely eliminate the possibility of carb troubles. When it was running, it ran rough. Have to let it warm up a little bit before it goes to idling rpm, usually under 1,000. When it's hot, idles above 1,000. On the road, it's fine when once it's warmed up. But if you were to get on the throttle, it'll bog down a little bit before hitting it off, like it would have too much or too little gas.

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