Bad TCI?

[joenurse]

First, after reading the most recent posts, I will start off with a re-introduction...

My name is Joe. I am an emergency nurse working in Frederick, MD, and I live in Falling Waters, WV. I purchased my 83 Vision in April, and have put 3000 miles on it in the last 4 months. It is basically a stock bike. It has an aftermarket seat with a cafe racer look (I will post pictures), and a Tim Parrott stator. I put a set of throw over saddlebags on it, and bolted a black Rubbermaid ActionPacker container to the luggage rack as a trunk. The rev limiter wire was cut and taped off 2 months ago.

The issue I have is that the bike drops a cylinder and the tach drops to zero intermittantly. Sometimes it is more like a surge (with the tach needle bouncing), sometimes it drops to zero for a short time (seconds), then runs normal, sometimes it stays at zero, then runs normally after restarting the bike, and sometimes restarting the bike doesnt do anything, and only patience rewards me with the dead cylinder restarting (minutes later). I will restate that I have cut the rev limiter at the TCI and taped it off, so thats not the problem. Also, this seems to usually happen when the bike is cold.

If this sounds like a faulty TCI, does anybody have a good used one I can buy? If not, where should I be looking next to diagnose the problem?

And, if there are any Visionaries within a couple of hours of the Eastern Panhandle of West Virginia, I would love to get together for a ride, or just to compare notes.

Thanks,
Joe

[Walt_M.]

Have you put new plug wires and caps on it?

[QBS]

Joe thank you very much for the thougher introduction.  The tach recieves its' signal from a wire that branches off of the low voltage side of one of the spark coils.  Don't remember which one.  Clean all the low voltage connections at the spark coils and the frame ground connection.  All this is located under the tank in the steering head area.

I've had two TCI failures.  Both happened out of the blue with no warning whatsoever.  The first one happened after filling up the tank and prepareing to leave town on a 2500 mile trip to West Texas.  The bike was loaded and we were headed out.  The next planned stop was 160 miles down the road.  Praise God that the TCI failed at the gas station two blocks from my home.

Both TCIs failed so that the bike would start and idle fine.  When the rpm was raised to 2k rpm the bike switched to running on one cylinder.  As soon as the rpm was allowed to drop below 2k rpm is would resume idleing as normal.  Nothing could be done that would change this condition except replacing the TCI box.  I now carry a spare known good TCI it the taillight storage area at all times.