Article as promised - very thorough. Gives a nice variety of trigger circuits that could be used in other projects.
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Other ignition options
- Thread starter scott s
- Start date
mike in idaho
XS650 Addict
I copied a design by one of the inmates here (mrriggs) a few years back, using a GM four pin HEI module and a GM coil for My '79 special: http://xs650temp.proboards.com/thread/7899/19-junkyard-electronic-ignition Made a bracket to hang the coil off the horn bolts and The HEI unit bolted to the original coil mounts. It was a snap to put together, following his posts. It started easy, idled
nice and pulled like a freight train. Think I'll build another setup for My '78 XS650E when I get caught up with work.
sleddog83
XS650 Addict
Just to throw another spanner in this.... my preference is to concentrate on the TCI ignitions. I think it may be possible to reverse engineer them and provide a resource for repairing them. My TCI igniter failed this spring. I tried the usual repairs for it and after no success, bought a Pamco kit. I have noticed that the camshaft based advance is not as good as the old TCI. The timing is just slightly more wobbly. I would like to go back to the TCI eventually.
I think there are lots of options out there for camshaft/Hall effect type systems. If there is anyone out there interested in sharing work or knowledge on TCI issues let me know. I have a background in electronics.
Sleddog83, good idea. But we need to identify which TCI to go with. The XS650SH TCI contains a proprietary IC (Quad Comparator incorporating a mystery circuit) which is no longer available. I believe one of the later XS models has a quad package with a modern equivalent available. But then these XS TCIs have very little in the way of a timing advance ramp. It is more of a switch from idle advance to max advance at something like 1800rpm. A bit primative but still a step forward from running the bike at full advance over the entire rpm range including idle.
I think Boyer is a good choice but as you and others have pointed out a crank based trigger is usually better/more accurate than cam based. Not being a racer I was happy with the Boyer system which I believe ramps up the advance in 50rpm steps.
The XS TCIs also have a no longer available switching transistor. However there is reported to be a suitable modern alternative with good characteristics resulting in a very good spark (ST901T - used in many small modern electronic ignition systems). I have tested the ST901T and it does work.
I think Boyer is a good choice but as you and others have pointed out a crank based trigger is usually better/more accurate than cam based. Not being a racer I was happy with the Boyer system which I believe ramps up the advance in 50rpm steps.
The XS TCIs also have a no longer available switching transistor. However there is reported to be a suitable modern alternative with good characteristics resulting in a very good spark (ST901T - used in many small modern electronic ignition systems). I have tested the ST901T and it does work.
sleddog83
XS650 Addict
After I got the Pamco kit working on my bike, I hooked up the busted TCI igniter and looked at it with my oscilloscope. The pickup pulses were getting into the igniter ok but not making it past the IC. The IC could be at fault or possibly one of the tantalum caps attached to it are bad. Not sure what the value of those caps are, no legible writing on them. If anyone else knows, let me know. Those caps could be part of an rc timing circuit?
Anyway I bought a 6 wire igniter off of a 1980 bike. The circuitry is slightly different. The IC looks to be easily sourced if I have to repair it. I will try scoping it on the bike when I get a chance. I will do some timing measurements on it when I get a chance.
Anyway I bought a 6 wire igniter off of a 1980 bike. The circuitry is slightly different. The IC looks to be easily sourced if I have to repair it. I will try scoping it on the bike when I get a chance. I will do some timing measurements on it when I get a chance.
You could be onto something there, sleddog83.
Back in the early-mid '80s, we used "egg shaped" tantalums as decoupling caps on our computer circuit boards. The field techs, and an industry alert, reported high failure rates of those caps. We immediately discontinued those in the factory, used something else.
That would be about the same timeframe of the later TCIs...
If you search for the XS TCI on Google then a lot of images come up. You may be able to read the values from these photos. I must have another look myself and try to identify which model has the easy to obtain IC replacement. I know there is one because I bought the IC equivalent for it by mistake a couple of years back thinking it was the same as on the SH model..
Maybe Ignitech is a good option, at least when using a PMA with a trigger "lump" on the rotor, ar maybe even the stock TCI trigger setup. Being digital and programmable, you can get whatever advance curve you want, up to static max advance,of course.
http://www.ignitech.cz/en/vyrobky/tcip/tcip.htm
Actually made in Europe (Czech Republic), not China......Personally, I believe the Czech make very good products, like Brno and CZ firearms, Skoda cars, machine tools etc. And Jawa motorcycles did indeed do well in ISDT 6 days back in the day
Heiden tuning did this setup for 277 degree rephased engines, using a Powerdynamo PMA.
http://www.ignitech.cz/en/vyrobky/tcip/tcip.htm
Actually made in Europe (Czech Republic), not China......Personally, I believe the Czech make very good products, like Brno and CZ firearms, Skoda cars, machine tools etc. And Jawa motorcycles did indeed do well in ISDT 6 days back in the day
Heiden tuning did this setup for 277 degree rephased engines, using a Powerdynamo PMA.
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yeah the CZ was a nice little gun once you had applied some carborundum or similar to the very slippery grips. I tricked a CZ out back in the 90s as a 'Practical pistol ' competition gun for my partner who couldn't get her tiny hands around a Browning HiPower or Colt 1911
Ahem but we digress ....
What would be interesting is to have an electronic ignition with a programmable advance curve
sleddog83
XS650 Addict
Sorry Paul. I meant to send a better reply, but ran out of battery juice on my tablet last night. Damn technology! Anyway my first goal is to try to understand the existing TCI modules. You have provided some interesting bits of info in that regard. I traced out the circuitry of my busted module(as best I could) and will do the same on the six wire unit. Sometimes, when you trace it all out and look at it with fresh eyes you find new clues. With those schematics and lists of substitute parts, hopefully people can repair more of their own igniters. The next step will be to map out the advance curves. I have seen some idealized curves on the internet, but can’t imagine how these crude little igniters could ever do those idealized curves. The curve you suggest seems more likely. I have some ideas on how it should/could work but nothing firm yet. Anyway, probably won’t do anything till winter. Too much good riding weather right now.
I wonder if the reference to Tantalum capacitors refers to the following diodes D1 - D4?:
I have on the back burner a crank triggered battery powered CDI ignition project.
However it is going to get a speed up as a mate will soon need an ignition.
Still thinking about the trigger everything else is sorted. The latest thought is to mount a magnet positioned on the alternator rotor similar to the TCI rotor. With pick up coil placed on the stator housing.
Later once the first system is sorted and running making another and adding a second magnet and pick up on a different radius to allow for a rephased offset.
This means a no charging however which can be a pain.
Will post up result when (if) it is running later in the year.
However it is going to get a speed up as a mate will soon need an ignition.
Still thinking about the trigger everything else is sorted. The latest thought is to mount a magnet positioned on the alternator rotor similar to the TCI rotor. With pick up coil placed on the stator housing.
Later once the first system is sorted and running making another and adding a second magnet and pick up on a different radius to allow for a rephased offset.
This means a no charging however which can be a pain.
Will post up result when (if) it is running later in the year.
sleddog83
XS650 Addict
No all the diodes are good. I am referring to c9 and c13. They are blue with a white top. No discernible writing. This is from a sk model(83). I did post a picture of this board elsewhere on this forum. They look a bit like tantalums.
We called them "Dipped Egg" tantalums.
I recall that the problem caps were yellow, or butterscotch colored.
I recall that the problem caps were yellow, or butterscotch colored.
Signal, very interesting. I am thinking ahead for a Virago ignition replacement which would be similar to an XS rephased system, just different angle involved.
Hi Paul, when I put it to one side it was looking very promising. Had the system sparking in a lathe, since then I have bought another trigger coil. The new coil has better mounts for mounting onto the flat end of the stator housing but I have not tested it with the CDI or put any more time into the scheme.
Maybe you guys can find some sense in these links...............some iof the links from the first link dont work any more but it does have some PDF files, for resisters and graphs, that download....
http://www.jetav8r.com/Vision/TCIRebuild/TCI_Rebuild.html
Found a link to RidersofVision.net and in Technical there is more on the TCI's and CDI's......
http://ridersofvision.net/
Under technical
http://www.jetav8r.com/Vision/IgnitionFAQ.html
http://www.jetav8r.com/Vision/TCIRebuild/TCI_Rebuild.html
Found a link to RidersofVision.net and in Technical there is more on the TCI's and CDI's......
http://ridersofvision.net/
Under technical
http://www.jetav8r.com/Vision/IgnitionFAQ.html
sleddog83
XS650 Addict
I have never heard that name before. I remember seeing those on some of the old RADAR equipment I used to work on,( back in the days when we actually fixed things). Any idea what values these particular caps should be?
sleddog83
XS650 Addict
I did come across some of this info in the past. The vision TCIs use some of the same components. Good info on darlington transistor substitutes and good general theory info on TCI systems.
Haven't a clue. The ones we largely used were decoupling caps, 1 per IC, 0.1uFD.
Are you testing them on a LCR meter?
I bought an LC200a for testing, has a broader range than most LCRs, fairly cheap.
Testing a rotor:
To add to 650skull's posting, more stuff attached.
