Electrical Problems. I need Help!

[jacker]

Alright, here is my problem. My '79 XS11 SF is acting up. I was having trouble with it running corectly, it was acting lean, then rich. So after some trouble shooting, I checked the spark. What I found was weak intermittent spark on #1 and #4. Coils right? Well, I checked #2 and #3 and they seem to be working fine. So I checked around and found the thread about checking coils. Read it and I think that I tested them correctly. I checked and yes, I have voltage going to the coils from the TCI box. When I checked the coils, the primary leads I had zero resistance on both coils. Does this mean that both coils are bad, and if so, why is the #2 and #3 working? Any ideas would be helpful.
Thanks,
Josh

[jeffe]

I had a weird problem this on my 78E. One of the nuts holding a mounting bolt had backed off. Tightened it up and was ok. Also have you checked the pickup coils. Check the thread on that

[Dragonrider]

Sounds like pick-up wires to me....

http://www.xs11.com/tips/repair/repair8.shtml

Check it out!

[randy]

Jacker,

Zero resistance on both coils ad one is working right? Possible you have your meter set to the highest scale? Try X10 or X100 scales.

I concur with the others, pickup coils or TCI are suspect. First clean all off your connections. That usually cures electrical woes.

A quick way to test your pickups and TCI is on my websiite. Use an ANALOG meter, not a digital.



Randys XS11 page

[jacker]

I had a few minutes tonight after work so I pulled the cover on the crank. Everything there looks brand new, all factory marks are there and none of the factory paint on the heads of the screws and bolts has been disturbed. Should I really be hacking into my wiring if everything looks good? By the way, this bike only has 5k miles on it. I have a manual on the way ( it is a new bike), and when I get it I think I will have a better grasp on things. Till then, any more suggestions? Oh, I will try to get an analog multimeter so that I can check the TCI. Will a digital not work? Anyways, as always thanks for the help.

[Dragonrider]

You can check the wiring at the pickups by working your way along it and gently pulling...if broken the insulation will stretch a bit at the break. This is a really common problem on the XS...

You could also check the ballast resistors and make sure they are to spec and hooked up (and not shorting to the frame or fuel tank).

[randy]

Jacker,

Digital meters are OK for checking continuity, resistance and voltage, but when checking the TCI in circuit and in operation the digital won't react fast enough.

A good old analog needle works better for this test. Play my TCI movie and you'll see what I mean.

PS you don't have to hack into the wiring to test the pickups, just attach your meter to the plug leads that are located under the fuse panel and then tug on the wiring at the pickups. Pickups should measure between 600 - 800 ohms. If your wires are broken you'll see the fluctuation in the meter reading as you tug.

[skids]

You can (I think) go further up the woring to the TCI box clip to measure the ohms and test for suspect connectios as well.

Originally posted by randy
Jacker,

(snip)PS you don't have to hack into the wiring to test the pickups, just attach your meter to the plug leads that are located under the fuse panel and then tug on the wiring at the pickups. Pickups should measure between 600 - 800 ohms. If your wires are broken you'll see the fluctuation in the meter reading as you tug.

[jacker]

Alright, so I worked on it again tonight. I checked the TCI box everything seems to be fine there. By the way Randy, this may sound like a stupid question, but the voltage is supposed to drop while turning the motor over, right? Anyways if that is the case, then the TCI is fine. I also checked the pickup wires, they are fine and there was no change in the ohms when I tugged on them. Thay stayed strong at about 784 ohms the whole time. So then I checked the coils again, and when I checked the primary wires they only had 1 ohm on each coils. Then I checked the plug wires, The coil that seems to be working fine had 68K ohms of resistance, which I think is too much? The other that has not been working had 28K ohms which according to th Ignition Coil Faq Thread is too much also. Are both coils bad, or am I an idiot and just can't figure this out?

[wildbill]

How does the plug caps look? They have been known to go bad as well.

[jacker]

I changed one of them on the "bad" coil. Have not bothered to change the others, because I figured it is bigger than that.

[TopCatGr58]

Hey Jacker,

Pull the caps off the coils, and recheck the secondary resistances. The plug caps usually run from 5k to 8k, which can add 10 to 16kohms to the coils 15k, making for around 25k or so. The 68kohm sounds suspect, but you say it's working!? The resistors in the caps can go bad, or get severely corroded and greatly increase the total circuit resistance. Both coils may be actually good, but the caps could be bad, and can be replaced!
T.C.