Bizarre TCI problem, short video

[DogBunny]

Reward of a million dollars to whoever can give me any help on this:

Video description:
Yamaha XS650 with TCI. Kick the bike and I get a spark. But then, I keep getting a rhythmic spark without doing anything. I hit the kill switch and get one last spark. Turn your sound all the way up, you can hear the click of the sparks. Video was shot in a darkened room so that you can see the sparks better. The spark plug is attached to a dual-tower coil, the plug is grounded to the engine. The other plug is in the engine.

Another video, same problem, slightly different symptoms:
I kick the bike and get a spark, then I pause for a moment. Everything seems normal. I kick the bike again, get a spark again, but then, I keep getting a rhythmic spark without doing anything. I hit the kill switch and get one last spark. Note that the frequency of the phantom sparks is much slower this time. In both videos, the phantom sparks seem weaker than the "real" spark.

Additional info:
When started, the bike runs fantastic. I have tried two different TCIs. My initial problem (which I still have), was this: In the morning, I would kick, and I would not get a spark. But if I hit the starter button, I would get a spark. This makes absolutely no sense. It was like the little electrons in the ignition system had to be "warmed up" by the starter motor. Once I got a spark by using the starter button, I could then go back to kicking and get spark. Once running, I would very occasionally loose spark, but only when cold. I know this sounds like a bad kill switch or wiring, but it is neither of those things, and besides, that doesn't explain the phantom sparks. Electricity is my specialty, and I believe everything is rock-sold. I have a good rare earth magnet glued on top of the rotor pick-up magnet. The pick-up coil is good. Two different TCIs do the exact same thing. Then, this morning, I start getting the phantom sparking that I showed in the videos. I haven't tried to see if the other TCI produces the phantom sparks yet -- I will probably have to wait until the "little electrons" in the ignition system "cool down" again.

Reward of a million dollars to whoever can help me with this before I remove the TCI system and put a Pamco in, which I sure don't want to do.

 

[Maurice]

Maybe this is related?

http://www.britcycle.com/Manuals/BoyerTroubleShooting.htm

Scroll down to "continuous sparking without cranking the engine".

 

[Maurice]

Then again that's assuming you didn't go over those already which sounds unlikely....

 

[DogBunny]

Maurice, interesting link. Here's what it said:


CONTINUOUS SPARKING WITHOUT CRANKING THE ENGINE: A poor battery with a battery charger connected or one or more bad cells in the battery. Battery is good, but I am going to charge it up anyway, and try again.A high resistance in the wiring circuit or earth return. I'd like to think I know how to ground, but anything's possible, so I will go through the grounds again.Check that the engine is earthed back to the frame and battery circuit. Plastic (powder coated) frames must have a good earth connection to the engine case and battery. A wrong type of ignition coil with a very low primary resistance (under 2 to 3 ohms) will draw a very high current and produce a large volt drop across the wiring. The coil resistance is 2.5 which is spot-on for a TCI ignition.All these will keep turning the ignition on and off, generating a chain of sparks.

Remember, there is the related problem of the bike not getting a spark in the morning with the kicker, until I "warm up the electrons" by hitting the starter button. I suppose that could be ground-related too, if I do actually have a ground problem. Seems to make some sense. I will investigate.

EDIT: I just noticed that is a Boyer link -- Still who knows, a TCI might produce the same symptoms from the same causes. At this point, I'm not dismissing anything.

 

[Maurice]

Yeah forgot to mention, it is TCI vs. boyer, but a badly wired boyer will do that, and they should be fairly similar in operation.

Good luck, does not look like a fun issue to chase down...

 

[xjwmx]

Reward of a million dollars to whoever can give me any help on this:

Ok, this pertains especially if the phantom sparks occurred with both tci boxes you tried.

One by one, until that symptom stops, disconnect each tci wire from the box and connect the box instead directly, not using the harness. That is, starting with ground, remove the ground wire that connects to the tci box and connect the tci instead directly to the frame. Continue with as many wires as necessary. Start with the easiest! (like ground)

This will isolate all the possible problems and let you figure out where the problem lies.

Small unmarked bills please. Sent to my cousin the rightful heir of the throne of Nigeria, so that he may have passage to safety, whereupon he will issue reimbursement directly to your bank by wire transfer.

 

[xjwmx]

Note that the phantom sparks are rhythmical. That tells me it isn't simply an intermittent connection of some kind. Probably has something to do with voltage level in the box and a poor connection that's altered the voltage level. If I had to guess I would say since it does it with two boxes, the problem is in the harness. Maybe just a bad tci harness connector. But the best thing to do is the test I described above.

 

[DogBunny]

That tells me it isn't simply an intermittent connection of some kind.

Yes, but could be a poor (high resistance) connection. I am going to try what you said. I did very carefully check and clean the TCI connector plug and its counterpart on the wiring harness, same with the pick-up coil.
What makes this hard to trouble-shoot is that it comes and goes quickly. Note in the second video how all seems normal the first time I kick, but not the second time. Same with the morning weirdness. Once it is warmed up, there is no longer a problem to trouble-shoot.
I'm going to get away from this for a while, taking the Bug Killer to Town Lake (Lake Lady Bird!), and run 5 miles on the trail...

 

[DIRTY DOG]

Hay dog if your grounds and power's to the black box and coil are ok I would check
the pick up coil on the stator I had a similar problem bad ground and pick up coil I could tap on it with a screw driver and I'd get a spark hope it helps

 

[xjwmx]

Town Lake (Lake Lady Bird!), and run 5 miles on the trail...

I'm missing Austin. I'm going to get back down there.

I had a bad connector in my charging. I was watching voltages and noticed it would change if I moved the connector just so. I had to take the connector out of the housing and re-crimp the connection to the wire and all was good. But that's for the fix possibly, not for the troubleshooting.

 

[pamcopete]

Reward of a million dollars to whoever can help me with this before I remove the TCI system and put a PAMCO in, which I sure don't want to do.

That's very hurtful, but I'll take the million dollars anyway.....

The TCI pickups can become slightly magnetized over time and falsely trigger in a number of interesting ways. Try using a degausing wand like we used to use with tape recorder heads back in the day to demagnetize the pickup.

 

[DogBunny]

Thanks everyone for the help.
Pete, you know I would love to put a Pamco in all of my XS650s, it's just a matter of cost.
I can imagine how a magnetized pick up might give a false trigger, but I'm having trouble envisioning how it would cause the no spark when kicked cold until I hit the starter button syndrome. I'm having trouble envisioning how anything would cause that, but I do know that TCIs can be extremely sensitive and finicky. I am not dismissing anything at this point, and will pursue the degaussing. I'm also going to go through the wiring again -- this discussion has helped me think of a few things that I want to look at.

 

[xjwmx]

Degaussing isn't going to do anything except possibly magnetize the pickup, which in fact probably wouldn't hurt anything.

A moving magnetic field causes the trigger. The pickup could have an actual magnet for a core and it would still work fine.

No spark from kicking unless you've hit the starter button is either just coincidental with not enough statistical samples for good assurance or else the starter drags the battery down enough to do something happy with the random voltages in your box, caused by most likely a poor ground. Anyway, you have my suggestion on how to systematically troubleshoot it. You can do that or you can blast at it with hopeful ideas, similar to replacing every part but cheaper.

 

[DogBunny]

No spark from kicking unless you've hit the starter button is either just coincidental with not enough statistical samples for good assurance

or you can blast at it with hopeful ideas, similar to replacing every part but cheaper.

I have two months of examples of the no spark from kick when cold unless I first hit the starter button syndrome. That was my original problem, and I did mention that in my original post. The phantom sparking just started this morning, or at least was only just noticed this morning.

I didn't say I was going to blast at it with hopeful ideas. I said that the discussion has helped me think of some things I want to look at. One is the grounds, and another is voltage drop across the key switch. I plan to try running direct jumpers from the battery hot to both the TCI and the coil.
Thanks for everyone's suggestions.

 

[retiredgentleman]

This is all very interesting.................I love a good mystery.

Its a little hard to believe that 2 TCI black boxes do the same thing. The pick-up coil and the wiring harness are a common item. I think an oscilloscope would be needed to see if pulses are being generated, by the pick-up coil, on the first kick of the day. Or maybe the pulses are generated but don't make it to the TCI box due to a wiring harness problem.

Try using a different pick-up coil??

 

[DogBunny]

retiredgentleman and everyone else, here's a little TCI story that I have been saving for a couple of years. I always intended to start a thread on this incident, I just never got around to it. You may think I'm crazy or a crackpot after reading the following, but I'm sticking to my story.

A couple of years ago, I bought a TCI XS650 that had only been sitting in a closed garage for a few short years and "ran great when it was put up." When I went to look at it I did a compression check, it was excellent. I then dropped a battery into it, hit the kill switch and start button, and got nothing. The owner was genuinely surprised at this. He truly thought that all it needed was a battery to crank over.

I took the bike home, and the only electrical problem was either a bad kill switch, a bad key switch, or a bad starter button. I don't remember specifically, but it was a switch, and a very simple fix. Other than that, the wiring was all original, and I did not mess with any of it.

I put carbs on it, and the bike fired right up. I dialed it in, and it ran great. The only problem, was that the instant you put took it out of neutral and put it in first gear (or second gear), it would loose spark and die. This was not a clutch or engine issue -- the clutch was adjusted properly and worked fine. This was definitely an electrical issue. The bike simply lost spark the instant you took it out of neutral. I don't remember if there was a clutch safety relay, but if there was, I by-passed it. I don't remember what other safety relays there were, such as a side-stand relay, but I bypassed whatever safety relays there were, all of them. I still had the problem.

I tried to wrap my head around what it is that changes electrically when you shift into gear from neutral. The only answer is that the neutral light goes out. Other than that, nothing electrical changes when you shift out of neutral. So, I removed the neutral light bulb from its socket. Voila, problem solved. I put the neutral light bulb back in, and the problem came back. I really couldn't believe this, but I did this over several days, and the results were always the same. I rode the bike, and the TCI worked flawlessly in all conditions as long as the neutral light bulb was removed. With the bulb in, the bike would die the instant you put it in gear.

BTW, the neutral light itself did work just like it is supposed to, and there were no problems with the neutral light circuit.

I really wanted a neutral light, so I ordered and installed the proper LED style gauge bulb substitute. It worked. Everything worked. I now had a great-running TCI and an operating neutral light.

Here's what I take from this: apparantly, when I would take the bike out of neutral, the voltage spike was enough to somehow send a bogus feedback signal to the TCI box that shut the ignition down. But LED lights draw so little power that when using the LED signal light bulb the spike was not enough to screw up the TCI.

Take what you want from this story. Call me crazy. But I was there, I saw it with my own eyes, and I say my story and assessment of it are correct and true. I sold that bike soon after I fixed it, I know the owner, and the bike has run without a hitch ever since.

The point of this story, and what I learned from it, is that TCI boxes can be extremely sensitive. Regarding what resistance coil to use with a TCI, pamcopete once said that you have to use a coil with the exact proper resistance (2.5), otherwise "the full TCI transistorized bag of tricks will not be utilized" (my paraphrase). I believe this. I believe a single poor (high resistance) connection or wire or ground can wreak havoc with a TCI. Or a switch with too high of a voltage drop, that doesn't allow full battery voltage to reach the TCI or the coil. Or because of various voltage drops in the harness, the coil hot being at one voltage, and the TCI box hot being at a slightly different voltage. Or even a neutral indicator light that causes too high of a voltage drop or spike when it goes on or off.

So anyways, I am going to re-visit some of the basics on the bike that has the current problem. I would love to put an o-scope on it -- there have been many times when I wished I had one, but I don't, and I have always been able to resolve my electrical problems without one. Thanks to all, this discussion really has been helpful to me.

 

[retiredgentleman]

DogBunny...................that's just an amazing story! Obviously these TCI circuit components become super sensitive as they age. You have a real challenge to solve your existing mystery.

 

[DogBunny]

Yes, that is a crazy story. You would think that hitting and then releasing the horn button would create a similar problem voltage spike, or going from high to low beam, but no. All I can figure, is that everything else except for the neutral light grounds through the frame. The neutral light grounds through the engine, which is also where the spark plugs ground.

 

[xjwmx]

Well, the TCI is NOT "obviously super sensitive as it ages", and so on ...

The issues described here were not thought through. And the proposed explanations make no sense, for example grounding to the frame vs grounding to the engine. The engine is obviously well-connected to the frame. So while it might satisfy some people, it is not the explanation, makes no sense, is not logical, is not the explanation.

 

[xjwmx]

TCI boxes can be extremely sensitive. Regarding what resistance coil to use with a TCI, pamcopete once said that you have to use a coil with the exact proper resistance (2.5), otherwise "the full TCI transistorized bag of tricks will not be utilized" (my paraphrase). I believe this.

Pete has a vested interest in seeing every ignition except his thrown into a bonfire. He walks a fine line of encouraging that while not doing so obviously.

I believe a single poor (high resistance) connection or wire or ground can wreak havoc with a TCI..

True. But the TCI doesn't own that property. The TCI is no more intolerant of sloppiness than anything else, I believe.