Fixing the ignition box.

[POOLBOY]

I just had to take mine apart.I have a 1981 Special, and after reading about all the problem's associated with the ignition box, I decided to see what was in there.
I striped mine down, and went over it carefully.Here is what I found.
This is a TCI box, not a CDI box, as most are calling it.CDI denotes a "capacitive discharge ignition", where a capaciter is charged, then discharged into a load(ignition coil)giving a large current pulse to the ignition coil.What we have here is "transistor control ignition",where the"point's" are replaced by a pickup coil, that triggers a switching transistor, to fire the ignition coil.Since the XS has vacume advance, there is no electrical advance built into the circuitry,at least as far as I can tell.
Where the CDI ignition system gives a boost in ignition current(spark), the TCI box mearly replaces the "point's" in a conventional ignition, and gives no real increase in current(spark).
It appear's that all the component's in the TCI box can easily be replaced, except for the amplifier IC. I cant find a source, or a cross reference for it,yet.
There are some component's in the 20 year old box that can age/wear out. Mainly the cap's.They are small in value, and being electrolytic, they can leak, or dry up.
Many of the small transistor's are of the age, and type, where failure was common.
All of the component's are subject to vibration failure.
The board uses feed through connection's from one side of the board to the other, and these type of connection's fail regularly.
Almost all of the solder connection's,especially the high current one's,and the connector's, need to be cleaned and resoldered.
The board is coated with a sealent to prevent corrosion,this can sometimes make resoldering difficult to do properly.
I wonder how many bikes are acting up due to weak spark due to aged component's, or bad connection's in the box? Weak/intermittant spark doesnt get any stronger with higher rpm's!!
I am trying to "reverse engineer" a schematic diagram of my box, and I will make it available, when it is perfected.
If anyone has a box they would like to have looked at, or if you would like help repairing your's, feel free to email me.
I have the equipment to test individual component's in an ignition box, but I only have my bike to test the box on.

[Shuriken]

Sure thing. I think you are right on the money with this.

Even if you can't reverse engineer the box, the details you make available will help us all.

Pretty soon, everything on this bike will be scarce, not just the carb diaphrams. But fuel injection possibilities can replace the ailing carbs, and if we can all work something out for the TCI box I think we'll have something. What will be next?

Keep up the good work.

Ben
'80g standard

[Snow]

UltraMegaSquirt will solve all our problems

[nashville_bill]

I'd like to have a schematic and diagrams of the waveforms at different places. I have an oscilloscope and have been thinking about using it to get a set of working base waveforms to use in case my ignition box ever had a problem. Maybe I should get off my ___ and do it.

[wildbill]

I`am glad somebody is looking into this.Sooner or later if we hang on to these bikes will no longer be able to get these parts after all things do wear out.Keep us informed on how it is working out.

[POOLBOY]

Thank's for the support.

With summer coming on, I cant be sure when I can get the "reverse engineering" done on the box.
I have 30 plus years of experiance in electronic repair under my belt(plus about 100lb) .Basically what I am saying is the box doesnt look too intimidating to me. I have been fixing discreet component board's for a long time, and if I can help someone, I would be happy to do it.I intend to run my XS with my stock, unmodified box, for a bit, then replace all of the component's in the box that might be "aged" and see if there is a difference.
I just hope all this B.S. is worth it, as my local bike shop has some pretty good looking deal's going this month.All there bike's are running, and mine not.
***********************SPLASH*********************

[terrydavis]

Fried T.C.I. box

Hello pool boy, last year-2003,I came across a used and abused 1982 xj1100j for $500,I like this bike alot. The only problem I have is with the T.C.I box, I've gone thru two of them.Everything seems fine while running around town - but if I go on a longer run - out in the county,the bike then runs only on two cylinders and then dies. Twice this has happend to me - at $250 per box. I have no idea what is causing the boxes to fry. Can you help me, also are you able to repair the box that I have, thanks - Terry.

[sksxs1100]

Re: Fried T.C.I. box

Originally posted by terrydavis
Hello pool boy, last year-2003,I came across a used and abused 1982 xj1100j for $500,I like this bike alot. The only problem I have is with the T.C.I box, I've gone thru two of them.Everything seems fine while running around town - but if I go on a longer run - out in the county,the bike then runs only on two cylinders and then dies. Twice this has happend to me - at $250 per box. I have no idea what is causing the boxes to fry. Can you help me, also are you able to repair the box that I have, thanks - Terry.

Welcome to the best source of info (not to mention great people) I have found.
always keep an eye on ebay for the boxes... I have seen them go any where from $20 to $100... alot cheaper than $250

[randy]

Here's a clue about frying TCI boxes. Anything that will cause the box to draw excess current will fry it. Things such as the wrong set of coils (low Ohms), or loose or corrroded connections inside, which can heat up. If you'd like to send me the box, I can take a look at it and let you know if it's repairable. I have repaired two in the past and both times the problem was the final output transistors. These are the final link from the box to the ignition coils and are the most likely components to "fry".

If you're interested, e-mail me a PM.

Randy

[ratbyk]

TCI Box Repair

Randy, you are proving to be a multi talented guy. Between stainless brake hoses and black box repairs you may help to keep these old bikes going for another 25 years.
Way to go!!!
Ken/Sooke

[randy]

So, I assume the lines are OK? Or are you still waiting for them?

I had an 81 Special between 1988 and 1996. I had the box failure twice. Both times just prior to a trip to Americade East. The first time I went the junk yard route. (This was before E-bay $120!). I got through the trip and the repaired my original box after I got home.

I kept running the junk box for a couple of years until it crapped on me, then I repaired it. By the time I got rid of the extra box, E-bay was in full swing and I E-bayed it to someone in the UK. I hope it's still going!

If I can help someone, let me know.

Randy

[rneal55555]

Has anyone ever found used an aftermarket Ignition System? There was a post on the XS 650 list I'm on about using a Newtronincs Electronic Ignition.[URL=http://www.motorcycle-ignition.com/default.htm] He was replacing points and there website says that is what the kits is for but I wonder, if our ignitions are not actual CDI units we should be able make it work. Looks like they cost about $150 might be a simple way to replace 25 YO electronics with all new Stuff.

[chevy45412001]

aftermarket ignitions

There are aftermarket ignitions out there that can be addopted to our machines.Dyna is only one company that makes ignit. for cdi or inductive type ignit.There are others.You smart guys can shed more light on that for me not so smart guy..

[randy]

For those of you who have opened their box, I have encountered two types. The early, fully transistorized and the later, Hybrid LSI / transistorized.

The fully transistorized (up until at least 2H7 ('79) is identifiable by, just as it sounds, 10 black transistors on the board ( three-legged, each about the size of a pencil eraser ) and two BIG ones at one end of the board. The BIG ones are the output transistors.

The Hybrid type ( beginning I think in '81) has one integrated circuit in the center of the board and the Biggies on the end. The integrated circuit replaces some of the transistors used in the early models.

I have had success repairing the early type, and I've seen the guts of the later type, but don't have one handy to troubeshoot with. If any of you have one that you've pulled because it's bad, please send it to me. I can then start searching for replacement components. You've got nothing to lose, and maybe a repaired TCI box to gain, and we can all benefit from the knowledge to be had.

Randy


Waddaya say? - PM me.

[desert1]

Another way

I had a website wrote down on a scrap of paper here somewhere but I cant lay my finger on wright now about repairing CDI boxes......anyway, the way this company goes about it and quite succesfully so they claim is open up the top of the box with a dremel tool going in no further than 1/8 inch and removing the top cover completely then testing and replacing components as needed, then you reglue the top back on. Post the site if I can find that paper.
I have two non working boxes that I will hang onto for now....just in case.
Bruce