TCI box - a successful repair, electronic ignition, ignitor

Yeah, I'm not too sharp with the trouble shooting...more like a process of elimination.. I'll stumble into it in time... I hope:D
 
I already posted this info to another thread but thought it should be posted here as well.
My bike is finally running perfect :), the problem turned out to be the zener diode 'ZD4' which my friend replaced with a new zener (12V value). If you are having trouble with misfire/skip, but it clears up when the reg/rec is disconnected, try changing this zener. On my TCI board it is the first component in from the black/white wire and I believe it controls voltage on the board...a bag of two 12v zeners can be found at Radio Shack for a couple bucks..
 
I've fixed car circuit boards by resoldering all the componets. The expensive main relay in Hondas is notorious for intermitant failure and wierd problems and codes. I just resoldered my last board rather than replacing and the relay was fixed!

The power transistors can pop in the TCI. Solder in a modern replacement (better) and maybe use a heat sink on the new transistor so it can handle a lower ohm coil without over heating.

A Pamco is a great points replacement idea but I've always questioned a Pamco as replacement for the TCI. It kills me when folks repalce the TCI with a Pamco. I wish everyone would send their unused TCI bits to me! There are many reasons the TCI is a superior ignition and well worth learning how to fix it. Thanks for the post xjwmx.

Tom Graham
 
My ignitor box looks like the diodes were already replaced. I picked up the transistor @ radioshack. Hopefully it dont rain tommorow and I can work on stuff.
Cool.
Srinath.
 
I have replaced what was an obviously fried Zener Diode in my '81 TCI box. In testing this component I have a few questions.

When I use my multimeter on 'diode check' function on an unconnected Zener Diode it shows "1" in one direction, and 944 in the other.

When I use the same function to test the ZD connected in the TCI box I get 564 going one way and 969 going the other way. The box is not connected to the bike's ignition system.

I read the 'all about circuits' section about diode testing but it didn't make sense to me. Was wondering if anyone can help me interpret my readings and see if this diode is still good after installation, that is, what might the 'correct' readings be?

Thanks,

n
 
nishgriff;

You can't test a diode when it is connected in a circuit. There may be parallel paths through other components which affect the reading.


I haven't measured a zener diode in a long while, but what you measured seems to be appropriate.

The "1" is actually an I for Infinity...............in other words the meter finds the diode to be open circuit in that polarity (reverse bias), which is normal. The meter does not have enough voltage to cause the zener to breakdown.

The 944 is the forward voltage (944 millivolts) measured as the diode conducts in that polarity (forward bias), which is normal.

You would have to have a circuit diagram in order to interpret what is normal from a circuit point of view, but I don't think the circuit diagrams are available anymore.
 
Help. For those of you that have this type of TCI board...could you tell me what this circled part is? Mine shown in the second pic is so melted I can't read the component numbers or location number. Thanks in advance. I'm hoping I can just replace this component but who knows what else is melted. Also anybody know of a good way to remove all the black melted crap? Thanks.

Update: This seems to be a resistor but i'm not sure of the color code. Does the top most band look green or grey? Green then red would indicate a 52,000 ohm, while grey then red would indicate 82,000 ohm, or it its blue it would indicate 62,000 ohms..if I'm reading this resistor guide correctly. The third band (black) is the multiplier (0) and the last band I think, going off this picture is gold representing a 5% tolerance.

Anybody willing to take an ohm reading on this thing or verify the color of the first band.

252-101111151143.jpeg

252-091111195951.jpeg
 
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That's for sure a resistor. Color code chart:

resistors_table05.gif


The colors I see in the upper pic are orange/blue/gold.
Orange = 3.
Blue= 6.
Gold= multiplier of 10. 36 x 10=360 ohms, if I have read it right.

Good page on how to ID resistors: http://www.mikroe.com/old/books/keu/01.htm

Given the size, I'd say it's probably a 1 watt. As I understand it, you can go bigger (say, a 360 ohm 2 watt) and not hurt anything but if you go smaller it'll probably pop quickly. A 1 watt would be a 1W136, a 2 watt would be a 2W136. PDF of resistor sizes:
http://www.sourceresearch.com/nte/nte-pdf.cfm?pdfpage=onew.pdf
 
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I'd say it's an 82 Ohm and that's what I measured. I'd say the first color is actually grey. There is some discoloration from the protective coating, but these pics may help.

Kent

P1010740.jpg


P1010739.jpg
 
Those are much clearer and you are right. I can see the gray band now. That makes the gold band the tolerance band, not the multiplier band. Now that the resistance is known, measuring the length and diameter of the body of the good resistor will determine what wattage it is.
 
Thanks Kent. That helps a lot. Hey when you converted to the Pamco how difficult was it to add the advance rod and the other missing stuff into the motor? thanks.

Now all I just need to find a local shop that has the right resistors. Radio Shack only seems to carry 1/2 watt and this is definitely bigger than that.
 
i have a 82 model with the "5V4" TCI box and up until last night and now again it has yet to send a spark to the plugs.a motorcycle mechanic friend came over last night and checked this and that with a meter and determined that the cause of the lack of fire was the TCI- the coil and pickup coil both tested good with current to the ignition coil.
after we finally got the box off the battery box he checked the connertors with a meter and wiggled this and that and low and behold we plugged the box back in and there was spark at the plugs. he said the white wire with red trace was suspect and probably needed re soldering, which we redid today at the shop- now no fire again!
i replaced the 4 diodes in D1 thru 4 thinking that might be it. still no fire.

any thoughts? i sure hate to ebay another box.

they had a TID 12 box at the shop but the wiring termils is different- the 12 box only has 5 wires and the 5V4 has 7.

and input appreciated.
 
Mookie, as your mechanic wiggled the red/white wire and it worked, then after soldering it didn't then I might suspect the red/white wire. Hook a ohm meter to it, then wiggle the wire. If it gets then loses continuity as you wiggle the wire, then replace the red/white wire.
Could be broken inside the cover.
Leo
 
About resistors: if you can't find a, say, 1 watt resistor can you use two 1/2 watts in series in its place and accomplish the same thing? Reason I ask, my TCI has 2 resistors in the same position that Kent's box has the single large one. I *think* that power coming in goes through one, then the other.
 
Read somewhere you can go bigger in size and it won't effect things but smaller is a no-no. Just get the ohms right. I went to get mine from a local electronics shop and the guy just gave them to me saying it cost him more to bother ringing me up.
 
i have a 82 model with the "5V4" TCI box and up until last night and now again it has yet to send a spark to the plugs.a motorcycle mechanic friend came over last night and checked this and that with a meter and determined that the cause of the lack of fire was the TCI- the coil and pickup coil both tested good with current to the ignition coil.
after we finally got the box off the battery box he checked the connertors with a meter and wiggled this and that and low and behold we plugged the box back in and there was spark at the plugs. he said the white wire with red trace was suspect and probably needed re soldering, which we redid today at the shop- now no fire again!
i replaced the 4 diodes in D1 thru 4 thinking that might be it. still no fire.

any thoughts? i sure hate to ebay another box.

they had a TID 12 box at the shop but the wiring termils is different- the 12 box only has 5 wires and the 5V4 has 7.

and input appreciated.


I like to switch a meter to the beep setting and connect each end with clips and wiggle things until the beep is interrupted. That will show you the actual bad connection pretty fast. Yours should be an easy fix, so I wouldn't jump on an ebay one immediately. But if the price is right it's always good to have a spare around.
 
thanks everyone-
i've wiggled and jiggled wires til i'm tired of it.
decided to work on another 650 for a spell...
points ignition!
th_IMG_0136.jpg
 
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