I could use some help guys

[yuddy]

Hi all,
I keep having the same darn problem with the bike suddenly only firing on two cylinders, then just as suddenly, back to normal.
I have checked, re-checked, re-checked re-checked, then
re-re-checked the pick up wires and still cannot find a break using the "pull till it hourglasses" method. I'm afraid to pull to hard.
I am going crazy trying to fix this increasingly annoying problem.
Could somebody please help before I go completely insane?????

Whats really weird is, I have put on about 3,000 miles since the last time this happend. Sometimes it happends within the same day, but never seems to last very long before getting back to firing on all four again.

I know it could be several things, but I just don't know where to go from here, could the carbs cause this?

Any suggestions would be greatly appreciated.
Ed.

[Ken Talbot]

Ed, see if you can find a piece of similar wire, say about 6 to 12 inches long. Grab it securely with both hands and see just how much pull it can take before you break it. Pay attention to how much (i.e. very little) stretch there will be. You won't need to pull quite that much to check for a broken wire in your pick-up coil leads, but you'll have a better idea how 'non-fragile' those leads are if they're not already broken inside the insulation.

Then, just for something to do, re-check all of the connectors in the ignition wiring. (You did check those all first, didn't you?)

[chopper]

use two safety pins and a multi-meter,check the wire for continuity,put one pin at one end then using the other pin work away from it towards the other end.

[uk1.1s]

Intermittent electrical gremlins

Looks like you probably do have some of the famous XS pick-up wire problem.

Just to really throw the cat amongst the pidgeons - are you sure it's not a problem coil? I had an intermittent fault on a coil a few years ago which drove me mad.

Of course going through the whole ignition system will be a pain, but give both your coils a health check too. If you are fortunate enough for the problem to be there as you are checking the system, check the resistance readings for the high tension and low tension sides of the coil circuits while you are at it.

Should only take a few minutes and at least rules out another possible cause.

Let us know how it goes.

[yuddy]

Gentlemen,
Thank-you for your reassurance that I am not crazy!!
I will try all above mentioned remedies, might take me a while as I am not to good with electrical stuff, but I will give it a try.

I will keep ya posted.

Ed.

[Wayne]

You can do it Ed! Just keep close to your computer when you have no problems. We'll be here.

[yuddy]

Just as a side note, if all else fails it looks like bikebandit.com can still get a stock "PULSER COIL ASSY " for a 1980 XS1100G
oem part#2h7-81676-10-00 for $100.84
The drawing is tough to read, just enter the part# I have listed above.

Here is the link if anyone is interested

Pick up coil assy

[newmaac]

It sounds like you already have some good advice.
My two cents:
I would recheck the pick-up wires, using the hour glass method, then the safety pin continuity method. If that checks-out OK, It almost HAS to be a bad coil. There was a post back on the old site where a guy had a bad coil that tested OK, but when hot, would fail.
I would imagine that you could get a used set from someone here, to swap with, in order to test this theory.
I have a used set of Dyno's, but no extra stock coils.
Let me know if you want to borrow or buy some Dyno's.
Mike
by the way, how is it that you know that you are dropping two cylinders? Do you know which 2?

[yuddy]

newmaac (Mike),
I did the old "spit on the hand and touch the pipes trick",
If I remeber correctly it was # 2 & 3.

Starting to think you are right on with the coil thing.
Are you selling those Dyno's?

Ed.

[chopper]

swap your coils over see if it happens to 1 and 4

[Dragonrider]

Check the ballast resistors and the wires to them, and the plug in the wiring harness (left side, under tank).

From the "been there done that" file

[yuddy]

Rut Row,
Ballast Resistors???
Now I'm really lost!

[sixtysix]

Theres only one ballast resistor and it is used to cut the running voltage on the coils to approx 6 volts. The resister is by-passed at start up to allow full voltage to the coil and allow a stronger spark. Cutting the voltage makes the coil last longer. At least that is the way I understand it.

[newmaac]

Ed, the Dyno's are just my set of "back-ups". I think that I paid 15 or 20 bucks for them.
If you get to where you think that it IS one of the coils, I would be happy to loan them to you. If that DOES fix the problem, you can reimburse me for what I paid.
#2 and 3 cylinders do fire from the same coil by the way, you probably already knew that.

Mike