CDI Unit , Ignitor, ignitionn box , ecu ,ecm Fix - It works!

JoshX

If you suspect your CDI unit may be bad, you may
not need to buy a new one.
I am going to tell you how to fix it.
Parts #s where to buy, everything. And for less than $2!
Read below.

I own a 1983 Yamaha xs650 Heritage special
The bike was acting funny sometimes, almost like it was
going to run out of gas sometime even when the tank was full.
Sometimes it would even stall on me driving down the road.
I tested the alternator, the rectifier, the coils, everything tested fine.
The last place was the CDI unit.
y CDI unit is labeled TID12-03 5V4-10
How do you test that?

The 2 most common problems with a CDI unit are:
1. Loose or bas solder connection somewhere on the board
2. Bad transistor

After checking all the solder joints I started testing and replacing the transistor.

Here is how to test:

The transistor is a chip that is attached to a shiny aluminum heat sink
and has 3 prongs that attach to the board that are labeled C,B, and E
Collector,Base, and Emitter

With a multi meter set to diode test >|
(diode has the symbol of an arrow pointing at a line)

Place the negative probe on the B and the positive probe on the C,
you should get a 1 reading meaning no conductivity

Now switch the probes (negative on C,positive on B)
you should get a 0 reading (or something other than 1)
meaning conductivity

Do the same thing with the B prong and the E prong
you should only get a 1 reading meaning no connectivity
when the positive probe is on the E prong

The transistors on xs650s are type NPN.

If you get reading that conflict with the tests above, or if you are unsure,
replace the transistor. It costs less than $2 at radio shack.
The part # is 276-2068
Here is a link:
www.radioshack.com/pro...age=search

The description is TIP120 NPN-D Transistor

Just unscrew and unsolder the old transistor and solder and screw in the
new one. Its a direct replacement.

After switching out the transistor on my bike, not only did it work again, but it felt stronger and now never falters!!

There are CDI boxes on ebay right now all for around $100
Hopefully my experience will save some people some hard earned
money. I know I did!

Good luck.

Josh Connon
Columbia,MO

Jack · Full Member Joined: Mar 15, 2005 Posts: 411

This is a big thumbs up on your part Wink

Should help members save a few bucks...............Jack

jimdi · 650Rider Supporter Joined: Oct 27, 2005 Posts: 512

Good deal - I have posted a number of articles on the bad solder joints on the CDI units - with the "mystery Stalling" eveyone (including me) seems to have.

ONe thing I would add - the harness from the CDI to the White connector -
has copper wire going into a crimped plated terminal (actually a number of them - 6 I think from memory.

Clean and solder these as well - they get a di-electric oxidization at the crimp points which impair contact from the signals comming from the pickup as well as to the output to the coils.

Cleaning just the terminals does no good - since the problem is under the crimp.

I did this - and resoldered - carefully the circuit board (CDI) solder joints - and my mystery dying problem went away for good!

Thanks for tech info on the transistors - I will file it aaway for future troubles.

- One last thing - as I understand the circuit - it is a simple switching on/off circuit - that switches (and advances) 12 volts to the coil. Unlike many CDI units - this unit DOES NOT amplify the voltage -
Do you agree?

brinkdw

I did the checks as prescribed in this thread. I ordered a new transitor and hope to have this bike running soon.I have a question on timing. Which is the best way to set the timing on a transitor (Electronic) 1983? I have replaced two pistons and realigned the timing chain properly. Which piston is concedered number 1? I put the top dead center with left piston seating on the bike. Is that proper? The bike fires but won't start completely. Question

xsjohn

I use a timing light hooked to the left plug. Check if it flashes on the F on the rotor at 1200 rpm. If it is real close thats ok. If it is way off then you will have to grind off the break off screws on the pickup coil and put screws in their place to set the timing. If you can't get it runing to check it I am at a loss to help. Bet it is not the timing if you havn't changed it. Starting spray may help.

John

westcoastchi

I wasn't getting spark at the plugs, coil checked out fine. Went to Radio Shack and the part number listed is the exact radio shack part.

I unsoldered the old transistor, measured where the new transistor leads should be bent at a 90 so it fit tight in the board and lined up with the small nut and bolt that holds it down, then soldered in the new transistor.

It worked just fine, plugs have a bright spark coming from them now. Bike fired right up. Thanks for posting this fix!!!

royfisk

This is very good information, thanks for the tip.

donniedark · New Member Joined: Apr 13, 2007 Posts: 6

Hey JoshX,

How interchangeable are these cdi units? I have seen used boxes for sale claiming to be off an "80-81" and others with the same number being off a later bike. Does any one know which numbers work on which year bikes?

I have one that looks like the transistor was very hot, hot enough to melt the solder attaching it's center pin to the board. The fuse to the ignition was also blown, installed new fuse, no spark.

I unscrewed the screw holding the transistor to the board and the green coating came off with the heatsink exposing the copper under the coating. Is the heatsink supposed to be insulated from the board or does it matter?

I know this was my fault as I had a battery charger on the bike that was set to too high a setting and left the key on.

Any info would be great appreciated,
Don

wayalive · Last edited by wayalive on May 5, 2008, 11:57 pm; edited 1 time in total

Hello all, two weeks into my first xs, and the cobwebs are stubborn!

Neck deep in the TCI Ignition Unit for a 1983 xs650 Heritage special. Gradually been running worse, with improper advance timing (checked with light), bogging, and misfiring. Now, getting no spark at all.

Having a problem with this test:

Quote::

Do the same thing with the B prong and the E prong
you should only get a 1 reading meaning no connectivity
when the positive probe is on the E prong

Here's the problem: with a new transistor (RS# 276-2068), it tests correctly before installation to board. No connectivity between E and B with positive on E. HOWEVER, once install it onto the board, there IS connectivity between E and B with positive on the E. If I remove the transistor, it will once again test as 'good.'

Questions:

- Do the above results indicate that TCI board is good?
- Do the above results tell me that something else is screwed up on the TCI board?

- Should I trash the idea of refurbishing this board?
- Any other ideas?

Thanks in advance.

wayalive

One more note... on this TCI board, with the transistor removed, the resistance between E and B is about 8,900 ohms.

I've read enough here to realize that I'll never truly 'bench test' the TCI. BUT, if anyone could confirm whether or not there should be connectivity between these points without transistor, that'd be great.

Some other fella out on the intarwebz wrote up some info on how he rebuilds Yamaha Vision TCI units. His second level of attack after the transistor replacement is to replace diodes and capacitors...

Don't know if I feel that hardcore. Think I'll reassemble when parts arrive, and go from there. That is for another thread...

By the way, thanks JoshX for the headstart on this!

royfisk

wayalive why not send that guy your unit and have him do it for you???

wayalive

Roy, I might do that if it becomes necessary. For now, I'm having fun diving into it, and learning some new skills. Definitely wanna be running before too long, though.

Just discovered that the existing transistor on my TCI was a different model that the one listed above by JoshX. It is a ETD41-035 not a TIP120. Same as some other yamaha tci's. Compared the specs for each, and these are pretty different transistors. Think I'll probably find and install a replacement for the one that was originally there, and see if it runs. Or blows up my new coil or something.

Strange that my 1983 xs650 Heritage Special has a different transistor than Josh's. Ignition unit even has the same numbers. Ahh, the mysteries...

phatdawg · Full Member Joined: Nov 19, 2007 Posts: 60

I have a 83 XS 650 that does not spark. I looked for the CDI unit. Is this thing mounted below and just right of the coil ? If so mine has the terminals C B and L (not C B and E). I also took some pics. Help me out if I am wrong.

I will try and attach pics:

weekendrider

phatdawg the CDI is under the battery box. About 4 inch square 3/4 to an inch thick. Look at this one on e-bay.
cgi.ebay.com/ebaymotor...:IT&ih=003
The picture that shows the board. I believe the thing they're replacing is in the upper left corner to the right of the screw.

phatdawg · Full Member Joined: Nov 19, 2007 Posts: 60

Thanks!

I get to take it appart even further!! Laughing

jimdi · 650Rider Supporter Joined: Oct 27, 2005 Posts: 512

What you have in your hand is actually the Turn signal cancelling unit. I have also found that when they go bad it is also usually just a bad solder joint as well. Just re-solder the wires at the top of the photo near your thumb tip.

phatdawg · Full Member Joined: Nov 19, 2007 Posts: 60

phatdawg wrote:

Thanks!

I get to take it appart even further!! Laughing

Well I got one of the screws off. The other is stripped a bit. That is a fustrating job taking off the CDI unit.

ay have to get some new tools just to get the dang thing off so I can test it.

Mad

snapcasezx3

anyone got any tricks to getting the cdi off or the battery box out?

jimdi · 650Rider Supporter Joined: Oct 27, 2005 Posts: 512

No - I know I did it from the right side - and had the airboxes pulled - while you have it out (because it is such a bear) make sure you clean and solder the terminals to the wires (normally just crimped)
(use a fine wire to release the terminals from the white plastic end - and just do them one at a time so you don't reverse any on re-assembly.

and I resolder all of the solder joints (carefully) on the circuit board too.
Take your time - low heat solder iron. Avoid the IC's just do all the other joints. Don't fry any componetnts.

Knock on wood - I haven't had one problem since. (over 2 years).

All that vibration - loosens and cracks the solder joints on the TCI pack.

It takes some patientence but it is well worth it.

wayalive

Aaaaack.... New transistor, careful resoldering, and now I have no spark at all. (was just having horrible timing issues before). Darn near ready to go boyer brandsen style. I do have two way conductivity between E and B prongs of ONLY WHEN transistor is on the board, so I'm thinking some other mystery component is fried. Can someone confirm this? Bike is an 83 heritage special.

TCI box removal - Best luck for me has been a long screwdriver up from the bottom between wheel and swingarm.

Thanks. you all Rawk.

xsjohn

Find another box like on ebay.......always need a good working second one to see where you are at....plus it is worth money and can always be sold or traded later...and a good investment for mental health.....two minutes to plug the second one in to eliminate that as a problem........me I am a parts swapper....saves a lot of gray matter....

YOu already have the best ignition system.......don't get frustrated and go backwards........

xsjohn

wayalive

xsjohn: thanks for the calming words of wisdom... I'll keep my eyes peeled, but the only one currently on ebay that appears a direct swap is going for $250. Makes it tempting to switch over to boyer for about the same cost. And honestly, I'm a bit wary about spending that kinda money on a used part with uncertain function.

Anyone happen to know if the tci units for all 1980-1983 are interchangeable once the couplers are re-mapped?

PS. Coil: GOOD, pickup coil: GOOD, kill-switch: clean and GOOD, most other contacts cleaned and treated with dielectric grease, plugs: GOOD, wires: GOOD, caps:GOOD

xsjohn

The early electronic ones had 6 pin connectors.....later they added the side stand no spark function......never had any problems with mine so don't know if they are interchangable.....I would suspect they are somehow......and after retarding mine 2 degrees it spanks perfectly....be careful about getting frustrated .....you might regret it later......yamaha understood the advance curve and I have customers that have found boyer doesnt.....very argumentive like everything else on this site but I know.......advance curve is critical on these or they run on crappy at cruise........see me about some needles when you get it in all in a stack....there is some things I have learned on that subject.........

xsjohn

wayalive · Last edited by wayalive on May 3, 2008, 8:28 pm; edited 3 times in total

I've read excellent reviews of your needles, but I'll worry about the carbs once I have spark again. I agree with your thoughts on having backups for crucial parts, for on the road swaps and troubleshooting as well. And actually, this drives me towards the boyer because I can get NEW boyer 'black boxes' for often much less than a questionable used OEM ignition unit.

As I understand it, (beware, I'm new here), the original electronic ignition can be considered preferable because it does not rely upon cam chain and other variables for its timing, correct? The aftermarket signal is coming further away from the all important position of the crank, hence the combustion chamber.

BUT. If I cannot obtain working replacements easily, I'm screwed. This is my main reason for considering an aftermarket ignition setup.

Someone should really be manufacturing new plug and play replacement TCI boxes for these bikes. From what I'm seeing, they could make some good money. Maybe I should just figure it out and start making them myself. We'll see....

Until then, I'm just an idiot with no spark, looking for the most reliable solution to igniting my engine, in a world where parts are limited.

Thanks much for all the replies and help so far.
Aaron.

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Yamaha xs650