Electrical problem - help!!!

[Keithh]

Greetings all! I once again come to the knowers of all things for help! I have a 1979 XS11 standard with a problem that is about to put me in a straight jacket! This has happened a few times now. I have the bike running fine, runs great on a ride. Put the bike away - the next time I try to start it - no spark! There have been a few times where it won't start and then it decides that it will. In the present situation, the bike started and ran a few days ago. Went to start it today, turns over, no spark. I have checked everything I can think of. Everything that should have voltage does, things that should be grounded are, emergency shut down switch checks out fine, has power to the coils, the red/yellow wire from the starter switch delivers voltage to the TCI when the starter is engaged. From what I can see, all the wires to the TCI check out as they should. The red/white wire delivers line voltage to the TCI when the key is turned on. Has voltage to and from the ballast resistor. A swap of TCI units had no effect. The only thing I am a little suspect of is that the battery when charged shows just over 13 volts, but quickly falls to 12.7. When the key is on, the line voltage to all the electrics is around 11.7. With starter cranking over, the voltage to the TCI is above the 10.5 death point (11.2 or so).

Am I missing something here? This works one day and not the next doesn't inspire much confidence in the machine. I'm temped to change out the wiring harness just to see if that fixes anything. I hate spending money only to be left with the same problem.

Any assistance appreciated - the men with the white coats are on the way!

Keith

[TopCatGr58]

Hey Keith,

First, have you done the solid ATCO style fuseblock mod or do you still have the OEM glass fuses/holders?

Secondly, have you looked at your pickup coil wires...see the tech tip in the FORUMS section on repair and diagnostic techniques....the other most common electrical gremlin for engine misses, poor performance, as well as intermittent starting.

T.C.

[GLoweVA]

T.C., Did you notice that Keith is from Va Bch ? !!! Yeah another XS'r here in hampton roads.

Did I read somewhere awhile back that during starting that the spark is different? something like it bypass the ballast resistor or something like that?

It sounds like there may be something wiggling loose or maybe the battery doesn't have quite enough juice. During the times that it won't spark, have you tried a 'jump' from another battery?

Keith, Maybe either T.C. or I could come by and help.
T.C.'s over in Portsmouth and I live near Pembroke Mall.
We've got another XS'r up in Hampton (Nightengale)(aka John)

We should all get together for a ride some weekend!

Edit: I was reading some of your past posts and noticed you had an issue with no spark before because of the 'kill' switch.
Could this be acting up again?

[Keithh]

TC/George,

Thanks for the tips - I'll try the jump start to see if it may be a weird battery - supposedly a fairly new gel cell, but it came with the bike, so you never know! I have checked the pick up coils several times in the past and everything seems to check out. Would love the get together if I can get the bike to cooperate! Once it is running, it never misses a beat - runs great! That's the crazy thing! Runs great, come back a few days later, no spark. I'm assuming the red/yellow wire from start soleniod is the resistor by-pass, as it only applies voltage when the starter is engaged. That seems seems to check out fine. I'll keep digging and try to stay ahead of the guys with the white coats!

I live over in the Western Branch section of Chesapeake. I think TC is about 10 minutes from me.

regards

Keith

1979 XS1100 Standard
1975 Triumph T150V
1975 Honda CB125S - for daughter to learn to ride!

[GLoweVA]

Thinking about it a little more,....
While riding it the Alternator is suppling all the juice, (and it runs fine, no skip etc. so the pick up wires and such should all be good then) but then when you shut it off, it seems that the battery doesn't hold the charge very well and then It won't respark.
Then again, have you checked you gaps. If the gap is a little to big, maybe the juice from the battery may not be enough to spark it, whereas the alternator will have enough.

Check that 'kill' switch again. It may have gotten corroded up again.

I think the least expensive battery I've found so far is one from walmart. (about $45-50)

How about a pic? Or at least a little one for your avatar?
Chesapeake, eh? Now we've got 4 of the 7 cities covered.

[crazy steve]

Poor connections are a plague on these bikes sometimes, and 'quick' checks with a meter may or may not show the problem. You might want to spend some additional time checking for the quality of your connections...

Try looking here: http://www.xs11.com/forum/showthread.php?t=35337
...and here: http://www.xs11.com/forum/showthread.php?t=35339

[Keithh]

Thanks guys - appreciate the help. Guess what - it lives! I need to do some looking at wiring diagrams, but here's the deal. After every check on the ignition side failed to come up with a problem, I decided to look elsewhere in the electrics for something that may be indirectly causing the issue. First thing to disconnect was the headlight relay. And it started right up! I put in a spare that I had, and it fired up. I put back the original relay - and it started! I'm wondering if the original relay was hung up and causing a ground or something. I did bring that relay back from the dead when I got the bike - all corroded inside - and it worked fine (so I thought) ever since. Gotta look into that more to be sure of the problem. I need the confidence that it won't come back!

Now, seeing how the tank is off, may as well sync the carbs!

Again - thanks!

[GLoweVA]

I suppose if the headlight relay was 'stuck' on then the headlight would be 'on' during the starting of the bike and that could cause enough drain on the voltage of the system to make it no sparky.

Obviously, most here know that the headlight relay is turned on by the output of the alternator, so as, the light shouldn't be on until the bike gets up to rpm.

Glad you figured it out.

Sync that thing and get out today. It's a great day to ride.
To bad I'm stuck at work and my bike is parked with a bald back tire.

[TopCatGr58]

Hey Keith,

Like George said, a stuck ON headlight could cause a significant voltage drain dropping the TCI down a bit? Glad to hear it's firing with the spare relay.

Chesapeake, Western Branch...yea that's a lot closer than George. I'm in the western branch area of Portsmouth, the Long Point housing area. If you'll send me a PM with your address, then I can look you up on mapquest and such for a future get together.

T.C.