Spark Problems

[AndyHartvig]

OK so here is where I am at. Two new(used) ignition coils that test out just like they should. I found a break in two of the wires from the pickup coil and reapired them soldering in a couple of new pieces of wire. I still have little to no spark on plugs 1&4. On 2&3 I have good steady spark when I crank the motor over but the only way I can get any spark at all out of 1&4 is if I just tap the starter button quickly I can get a spark every once in a while. I have the coils hooked up with the orange wire to the left coil and gray to the right coil. If I switch the orange and gray wires around I get the exact same issue only on the oposite plugs. So I have come to the conclusion that it has something to do with the orange wire. I've tested continuity in all wires from the pickup coil right up to the ignition box and then to the coils and everything seems fine. When I put a test light on the gray wire at the ignition box and crank the engine over the light will flicker on and off with the cranking of the engine which I am assuming is supposed to happen. When I do the same test on the orange wire at the box and crank the engine over the light just goes out. Could my ignition box be bad? PLEASE someone help!

Thanks!

[BA80]

Unplug the orange wire from the coil and see if it does the same thing. If so it may very well be you CDI. If it works correctly unplugged from the coil it'll most likely be a shorted coil.

[ViperRon]

Tci

I have read threw your testing and it appears that you have a problem with the TCI but I ask that you go back and test a few things before you get a new one. First of all these bikes are prone to having high resistance connection problems. Check the connections to the TCI and ensure they are clean. Check the voltage to to ensure you have 11.7 or better. Do not test with a battery charger make sure you have a real battery in the circuit. You can use jumper cables from a car but if the connection is poor the starter can drag it down. Check the main ground wire from battery to frame and the voltage supply wire and make sure connections are tight and free from corrosion. Then go threw the below checks from the troubleshooting section here on the site again. The Ballast resister can be removed from the circuit for testing but should not be left out. If you have done all the tests and you do not see anything out of tolerance then your next logical step is the TCI. Poor connections shorts miss wiring from PO's have created intermittant problems in bikes so even after all this there could be something over looked causing the problem. A secure source for getting a TCI is member ANDREASHWEISS. I had an inttermittant TCI and purchased the cheapest one from EBAY a new user and it was bad so there is no guarentee from many sources. If you get one get it from a source you have some faith in it's worth the extra few bucks. This is the best advice I have to give.



Remove each spark plug, ground it against the engine, see if you have a bright healthy spark. (Don't crank the engine with spark plug caps not attached to the plugs, or with the plugs not grounded to the engine, you could damage the coils.)

For those still with us, with weak or intermittent spark, or no spark at all, here is a simple ignition circuit diagram:


Ballast resistor (all models 78-80; 81 and on use different coils that don't require it) – check terminals; resistance should be 1.6ohms +/- 10%. The coils should have 12 volts with ignition on (coil side of ballast resistor red/white wire vs ground). The TCI cuts off current to the coils after a few seconds of the ignition being on but engine not cranking or running. When the motor cranks 180 degrees, the pickup coil signal turns the voltage back on, so you might have to crank the motor briefly to measure this voltage. If no voltage, you probably have a pickup coil or TCI problem. See the Battery and Electrical Tech Tips.

You can measure some resistances by pulling the plugs off the TCI unit.

All models have the same wire colors for the ignition coil primary windings:
Orange --> Red/White <-- Gray

Ignition coils: (Primary measured from plug at TCI, Secondary measured at spark plug wires - the caps are resistive, remove the cap to get a true reading)
1978 -1980 Primary 1.5 ohms +/- 10%, Secondary 15K ohms +/- 20%
1981 and later Primary 2.5 ohms +/- 10%, Secondary 11K ohms +/- 20%

Pickup coil wire colors:
E, F, SF: two pairs of Red/White <--> Green/Yellow
G,SG, H, SH, XJ: Orange --> Red/White <-- Gray

Pickup coils: (measured at TCI plug)
XJ 120 ohms +/- 20%
All other models - 720 ohms +/- 20%

[crazy steve]

Sounds like a bad box.... You could open it up and see if there's any broken connections internally (a problem these have been known to have) and maybe resolder any you find, but if that's not it, a replacement is in order...

[AndyHartvig]

How exactly does the ignition box come apart? I took the top off and all I see is the back side of a circuit board that doesnt seem like it wants to come out.

[crazy steve]

I haven't been unfortunate enough to have to do this repair yet, so I'm no help. A member here (DaVinci) has fixed these in the past and used to have a webpage with details, but it's no longer there. You might try PMing him and see if he can help you out....

[DAVINCI]

Don't try to remove the board, you can crack it and cause even more headaches.

Yes, I have lost my ISP and so my page hosting, but I can help you out. If you're handy with a soldering iron, you can do it yourself.

Have you any experience soldering circuit boards?

Try this: resolder (WITH NEW SOLDER) THESE PINS:



If you're scared, you can send me the box for evaluation. Let me know and I'll PM you my mailing address.

[James England]

I have a working box available .... from an XS1100 with ballast resistor and 1.5ohm coils, with mechanical and vacuum auto advance.

[petejw]

also check ur gap between the rotor and pick up coils,
28thou from memory.

[skids]

My volte is the ballast resistor if your model has one. They can short out to frame as I understand...

[skids]

The starter button is in the same housing as the kill switch. Maybe you need to clean it out. I think there is a denent ball on a spring to position the kill switch, so don't let that thing do the jack-in-the-box thing and launch the ball across the garage (tiny).

[DAVINCI]

Guys,

He's got problems on only ONE coil. Kill switch, Rotor and Ballast will affect both coils.

Ok, Ok rotor could be off on one. sorry.

[BA80]

My volte is the ballast resistor if your model has one. They can short out to frame as I understand...

The starter button is in the same housing as the kill switch. Maybe you need to clean it out. I think there is a denent ball on a spring to position the kill switch, so don't let that thing do the jack-in-the-box thing and launch the ball across the garage (tiny).

Those would affect BOTH coils, not just the one for 1 & 4 as he is saying.



Dang it Randy, you beat me!

[bikerphil]

Shot in the dark...

Try grounding the neutral indicator light wire, the one down by the shifter under the engine. This temporarily fixes the unexplaned loss of two cylinders whenever that lower harness down there gets full of water, either from washing or riding the bike. Couldn't hurt to try, btw the the neutral light will stay on in all gears.

Another thing to check if you haven't is the plastic PU coil wire harness connector behind the fuse panel. it often gets overlooked and needs cleaning.

[SFerinTEXAS]

What are the ohm readings on the p/u coils at the harness at the tci box. top 2 for 1 coil, bottom 2 for the other while manually rotating the advance? Almost always the wires even if you think they are fixed. No ohm test, no confidence that its not. Should be a constant reading in spec range , no blips.