Swapping spark plug wires... upgrade to Resistor plugs?

[hollywoodxs11sf]

Hey, guys. I'm in the middle of my "coil wire fix", and I'm not using the original spark plug wire caps. The manual states that these are resistor caps.

Since the new wires are non-resistor, will switching to resistor plugs do the trick?

What would happen with non-resistor plugs/caps? I'm currently running NGK BP6ES.

Do resistance values vary between plug brands?

I have no tester, so how will I know if the new plugs are the same resistance value as the caps I removed?


Thanks in advance for any help you can offer on the subject. You guys have been an endless cornucopia of knowledge/trivia in my trials with this bike, my favorite motorcycle ever. I really appreciae it, and look forward to the day that I have absorbed enough information so as to help others.

[Hobbit]

plugs

Hey Hollywood,
The main reason to have resistance in the secondary ignition system is to reduce RFI emmissions. However, it does actually help the ignition system to sustain the spark duration. Once a coil has enough voltage to jump the plug gap (the highest resistance in the circuit) the coil will discharge by oscillating quickly back and forth from the primary to the secondary (AC voltage) because the spark across the gap is now a conductor. The resistor plugs, connectors or wires control how long these oscillations last.

As far as measuring the resistance of the plugs, the value measured with an ohm meter is calculated based on how hard the meter has to work to put a (very) small amperage through the plug at the lowest voltage possible. (Called a static reading.)

When the engine is running, the dynamic resistance is quite different.

Short answer, some calibrated resistance is good in the secondary ignition, the heat range of the plug only controls how fast the center electrode releases heat to the cylinder head.

Did I answer your question? Or did I just ramble on to much?

[skids]

Re: Swapping spark plug wires... upgrade to Resistor plugs?

I have used resistor and non-resistor spark plugs after the coil wire modification. No noticable difference. I use stranded wire plug wires, like the originals, by Accel. There are some differences between the caps for Kohms. I have seen between 3kohms and 8 kohms. I use NGK and I think they are 8kohms each. No big deal. Just find the right length and angles.

Originally posted by hollywoodxs11sf
Hey, guys. I'm in the middle of my "coil wire fix", and I'm not using the original spark plug wire caps. The manual states that these are resistor caps.

[hollywoodxs11sf]

No Spark from 1 & 4.

Okay, guys, thanks for the knowledge about resistance values and spark plugs. I ended up going with non-resistor caps and NGK resistor plugs.

Now I've got a new problem. When I completed the wire swap, the bike ran perfect, better than ever. Smooth idle, no misses or backfires, powerful. It was great. Then it started raining, and I was forced to stop at a friend's house and my bike had to sit in the rain. When the storm blew over, I decided to ride home. The bike ran like crap and I figured out that the 1&4 plugs were not firing.

I thought the bike had water in it, and I gave it a few days to dry off. Still runs like crap. I tore it down to the problem coil, took it off and inspected my work. Die-electric grease was used, and it looks like everything from the wire swap is still in place, but I get no spark at all.

Do you guys have any leads as to where I should start looking? Do you think it's a bad coil, or possibly the ignition module?

Does anybody have a left side coil that would fit a '79 XS1100SF that they may be willing to part with cheaply? My big problem right now is my budget. There's no way I can afford new coils right now. Also, I don't have a multi-meter, which makes self-diagnosis very difficult.

[randy]

Ted,

Without a meter, it's very difficult to test / troubleshoot any electrical problem. You can, however rig up a test light with a 12V bulb and some wire.

To test the ignition module, for coil 1/4, unplug the orange at the coil. Connect one end of the bulb to the orange lead and the other end of the bulb to + battery post.

Turn the ignition on, the bulb should light. Crank and the bulb should flash if your TCI is OK.

Use the same test bulb to test the primary of the coil, just hook it in series with the bulb. If you get light, your coil is good.

HTH

[jeffe]

If you switch the input wires to the coils and also switch the wires to the plugs then try to start you can tell if the the suspect coil is bad. I'm probally making this seem pretty simple but it works. There three input wires to the coils. One hooks up to two wires, and the others are single wires. Can't remember what the colors are. Then just switch what plugs the wires go to. This has worked for me in the past. I know how it is to work on tight budget. Getting my old 78E back on the road has been fun. The PO parked her for 5-6 years with a 1/2 tank of gas. So I've had to resort to "on the cheap" methods serveral times. Good luck

[randy]

The 1/4 is ORANGE, the 2/3 is GRAY.

The common is RED/WHITE

[Hobbit]

ignition

Jeffe,
If you swap the wires like Randy suggests and the cylinders do work, then click on the "Tech Tips" on the left side of the page and look at the ignition pick up information.
Walt

[randy]

If he swaps coils, and it works then the pickup is good. The coil was bad.

[Hobbit]

Of course your right, I guess that I type faster than I think, I think?

[hollywoodxs11sf]

I tried switching orange wire for grey this morning, and still got no spark.

Does anybody have an old left side coil they'd like to sell me? Or even a right side... I could put my new longer wires on it.

Thanks for all the info. I suspected it was the coil. And after only 83k miles!!

[TopCatGr58]

Hey HollywoodXS11SF,

You said that you had done the replacing coil wire fix, and then used Dielectric grease! So...did you replace the entire wire from the coil, cutting into the casing partially per the tech tips, and such!? IF so...and then after the rain, perhaps some water got past the grease and INTO the coil. Maybe you could take the coil off, take the wire back out, and then inspect it for humidity where the wire was inserted!? Leave it out in the sun(oh, sorry, you're getting all of that rain right now ), or put it in the oven at very low temps to bake dry, or run a blow dryer at it for a while!?

Then reattach the coil wire, and test it for fire?? If it works, then use some SILICONE RTV to seal it where it attaches to the coil body!? Just another thought, since it WAS WORKING Prior to getting wet!
T.C.

[hollywoodxs11sf]

After applying the die-electric grease, I wrapped the heck out of the thing with duct tape (not intended to be a permanent repair, just to see if my coil wire swap was successful... I had planned on RTVing it).

When I tool it apart today, there was no evidence of moisture inside the unit, but I'm gonna try everything. I'll pull the coil right now and bake it in a slow oven for a couple of hours.

You think 225 degrees would be safe for the coil unit?

[TopCatGr58]

I would think that temp, or lower if you can, they sit on top of the engine and probably get exposed to temps in that range!!

Rain water has lots of minerals(pollutants), in it, and could have left a particle residue/trail along the wire and coil case, etc., causing it to short out somehow?? Good luck with the baking and reattaching the wires, Test it first, and if it then works, THEN Apply the RTV!
T.C.

[hollywoodxs11sf]

I was thinking it would have to be over 212 degrees to eradicate any water present.

If it doesn't work, I founs a guy locally that has "a bunch" of used xs11 coils priced relatively reasonably.