xs1100 ignition

[cywelchjr]

It was sparking with just the key on. I Hadn't even touched the start button yet. I put the key in. Turned it to on and then it started sparking?

For that to be happening, something has to be making and breaking the circuit at whatever rate the sparking is happening. Either the TCI itself, or the input coils or something associated with that. That spark is caused by the magnetic field on the primary side of the spark plug coils collapsing as the power is cut to them, this is either done by the power transistors in the TCI shutting off (normally under control of the input coils) or by a wiring fault of some sort, like a bad fuse). Do you still have the original fuse box? Or have you upgraded to a modern blade type fuse box? Bad blade type fuse holders or fuses could cause a symptom like this, and even the total lack of spark.

[Chadwic82]

Is there any way it could be the regulator or rectifier?

[cywelchjr]

With the bike not running it would be almost impossible for the regulator or rectifier to be doing anything. That said if you were to suspect that, you could unplug it and see if that made it stop doing it. It would be a simple enough test as it's just two plugs up under the tank.

[DAVINCI]

You could have seriously loose connections to the TCI. The only thing that would cause phantom ignition sparks is poor connections or the TCI has water, mold, corrosion, etc. on the internal circuit board.

BTW, don't try to remove the board, you'll snap it.

[cywelchjr]

You could have seriously loose connections to the TCI. The only thing that would cause phantom ignition sparks is poor connections or the TCI has water, mold, corrosion, etc. on the internal circuit board.

BTW, don't try to remove the board, you'll snap it.

Well at least the phantom sparks would go away then . Good point Randy, that was kinda my thoughts as well. That was why I mentioned wiring fault and fuse box. I know the fuse box can make the connection make and break rapidly if it's bad, as can, thinking about it the ignition switch itself.

[Chadwic82]

Well, I sold the bike last night so you guys will probably have a new member asking some of the same questions.Lol. I really appreciate all the help you guys gave me. This is a top notch forum!

[XSLevi]

the saga continues

Hello everyone, I am Levi, purchaser of Chad's bike which has been the object of this thread. First, I am impressed with the forum and community here. Now, as for the bike, it is still as Chad described it, no spark to cylinders 2 and 3. I Have checked everything previously discussed, and also have checked for continuity from the pickup coil up to the TCM. (cut tiny slits in the coil wire insulation to accommodate multi-meter lead) Coil Wires are all ok. (except for the slits of course.) Also, my ham-fisted efforts to examine the tcm have resulted in its destruction. Soooooo, If any one has an extra tcm for an 81 special, I'd be interested. Also, if anyone has any other ideas about what the actual problem is I'm all ears. As a last resort, I'm considering an after market ignition system. Anyone here ever installed one on an XS? Thanks to everyone still involved with the thread.

[cywelchjr]

The TCI for the 81's is a LOT harder to find and much more expensive than for other models other than the XJ's because of it being a single year unit that works differently than any other year model does, with the centripetal advance build electronically into the TCI using custom chips that cannot be replaced or sourced from anywhere else. And as far as I know there are no aftermarket systems for these bikes that don't involve custom work by the owner to build basically a custom EFI and ignition control system which will cost generally in excess of $1000 just in parts, not counting your time, and will take a good amount of experimentation and such.

The earlier models can have a replacement TCI built from a couple of GM ignition modules pretty easily, but the advance stuff is all mechanical on those.

Unfortunately it sounds like the TCI might have been the problem all along, but it's hard to tell, cause the were not done following the methods recommended in the troubleshooting guides on the site so it's unknown if the pickup coils themselves are any good or not, as it's more than just the wires (although those ARE the common fail point, but the way they are tested is to test the resistance from the connector back to the pickup coils and then tugging on the wires to see if they stretch as well and seeing if the values are right and stay that way while tugging on them).

[XSLevi]

cywelchjr: How do I test the pickup coils themselves? where do I make a connection with the multimeter lead? The thought that one p/u coil may be bad has crossed my mind, I just cant figure out how to test for continuity as they seem to be totally encased in tough plastic.

[XSLevi]

Also, I believe Chad tested the TCM according to the recommendations you reffered to:

After searching online for a solution I came across Randy Rago's site. Thats where I read about testing the orange and grey wires in which he stated that when the starter is engaged the voltage should fluctuate irratically which the wire feeding the coil for 1 and 4 did. The wire feeding the coil for 2 and 3 dropped to 8 volts and stayed there until I let off the starter then went back to 12v.

Are there other methods for testing/repairing the TCM?

Lastly, You mentioned earlier in the thread the possibilty of converting to the older style ignition with both centrifigual and vacume advance mechanisms, and use of the 2h7 TCM. If one were to do this, how much trouble would it be to fit the centrifigual advance mechanism?

Thanks for staying tuned to this.

[crazy steve]

There's two places you can check the pick-up coils; one plug is behind the fuse panel (along with the alternator coils plug), the other is at the TCI. At the fuse panel, it will be the plug with five wires (yellow/red, yellow/green, white/red, white/green, and sky blue), at the TCI it will be the plug with four wires (the sky blue wire will be missing; neutral light). Look for 720 ohms, +/- 20%. Pull the ignition cover off the motor and pull/wiggle the wires while checking to see if you have a broken wire. If you get a poor test number at the TCI (open, shorted to ground, high/low ohms), then test/clean at the other plug....

[natemoen]

Also, I believe Chad tested the TCM according to the recommendations you reffered to:

Nothing against Chad, but trusting some diagnostic testing to someone else is like having a doctor telling you you are going to die in a month and not getting a second opinion.

[XSLevi]

lack of ballast resitor?

One more thing guys, I cant find any ballast resistors on my bike. Does the 81 have ballast resistors? could this explain the downfall of the TCM?

[natemoen]

One more thing guys, I cant find any ballast resistors on my bike. Does the 81 have ballast resistors? could this explain the downfall of the TCM?

81 does not have the resistor because the coils are already 3ohm coils.

Why is it that you say the TCI is bad? What did you do to it?

[XSLevi]

I broke the board, severing the copper film in several places. I have just made arrangements to recieve a known good unit from DAVINCI, who I understand is knowledgable and trustworthy. Hoping this will solve the problem, but if not, at least I will have eliminated the TCI as a variable.