Topic: Need some help trying to start bike with suspected frigged kill switch

[b1jackson]

In any case, I suspect you have a poor connection at the harness black/wht wire junction.

Do you mean right at the connector where the 2 coil black/whites plug into the single black/white and then feed the harness or a junction further into the harness?

[scottly]

The double female bullet connector where the two black coil wires plug into the harness. If you unplug the two black coil wires from the harness, then connect them to each other, you should read 9.7 ohms between the yellow and blue wires. With the black wires connected together in the double bullet in the harness, it should read exactly the same, provided the yellow and blue wires are disconnected from the harness.

[b1jackson]

ok.  stand by.  Back to the shop I go!  Wish my wifi signal was stronger.

[b1jackson]

OK.  Thank you for the step by step.  Very helpful.

When the black/whites connected together = 9.7 ohms as you predicted (testing at the blue and yellow)

When black/whites hooked back into the connector and tested between the blue and yellow disconnected from the harness
= 6.0 ohms.  So a drop somewhere?

[scottly]

The resistance should be not be lower than 9.7. If there was a poor connection at the black wire junction, the resistance would be higher than 9.7. The connector ties the two black coil wires together, just like when when you measured 9.7 ohms.

[b1jackson]

not sure.  I followed your procedure but will re-try.

[b1jackson]

Here is the test with the black/whites plugged back into the harness.



And with the black/whites tied together outside the harness.

[scottly]

That has me baffled!??? The key was turned off, correct?

[b1jackson]

Yes, it was.

[scottly]

With both coil blacks disconnected from the harness and each other, measure the resistance between the coil blue and yellow wires, one at a time, to chassis ground. Should be no continuity, null.

[b1jackson]

Ok.  Another round of testing!  When my probes are touched, it reads .7 ohms so that number is subtracted.

With the coil wires disconnected from the harness, black probe to frame ground and red probe in yellow coil wire, reading = 0.7 ohms - 0.7 = 0 ohms

Testing the blue wire using the same process I get a null reading (same as if probes are touching nothing).

For another test, I hooked up the two black/white coil wires and tried again

Blue 5.8 - .7 = 5.1 ohms
Yellow 0.7 - 0.7 = 0 ohms

[scottly]

After spending all day staring at your last two pics and comparing to coils I had at hand, I found your problem: the bracket that attaches the coils to the frame is mounted backwards, pressing the coil wire(s) up against the bracket. The relief in the brackets goes towards the coils, not away from them.

[seanbarney41]

wow...I thought I was the only one dumb enough to make that mistake.  It took me about 12 hours to track that one down.

[b1jackson]

Corrected



And.............



spark on all 4!

[scottly]

 

[b1jackson]

wow...I thought I was the only one dumb enough to make that mistake.  It took me about 12 hours to track that one down.

Ouch....I will remain unscathed from the comment on my intelligence and once again thank Scottly for walking me through this thing step by step.  I've never worked on CBs before, had no clue about wiring or multimeter testing.  Bought it as a non runner and when it comes down to the coils, I put the bracket the same way the PO did with the Pamco and as you know, they hook up differently and I'm not sure the little lip in the bracket matters for them.

Yes, I had a short in the kill switch and obviously some other issues as well.  A tremendous learning process over an hour or so each evening. 

Tomorrow, I'll fire it up again for a real test drive!

[scottly]

Jackson, here is what I think happened:
The PO incorrectly installed the brackets when he mounted the new coils, and after some period of time the insulation failed on one of the black wires, shorting to ground. When you replaced the "failed" coils, you mounted the brackets the same way, only this time it was the yellow wire that was shorted to ground, which wouldn't blow a fuse, but also wouldn't make a spark. The big clue was when the resistance between the blue and yellow wires dropped when the blacks were connected to the harness; this could only happen if there was continuity between either the blue or yellow wire to ground. Don't feel bad, when I was looking at my old K1 coils, the bracket on the back was pressed up tight against one of the black wires, and I had never noticed before now.

[b1jackson]

I'll report back after my road test.  Dang this has been fun!

[seanbarney41]

wow...I thought I was the only one dumb enough to make that mistake.  It took me about 12 hours to track that one down.

Ouch....I will remain unscathed from the comment on my intelligence and once again thank Scottly for walking me through this thing step by step.  I've never worked on CBs before, had no clue about wiring or multimeter testing.  Bought it as a non runner and when it comes down to the coils, I put the bracket the same way the PO did with the Pamco and as you know,

no way dude.  You totally get the win here as I have no excuses...I have owned 13 or so of these in the last 7 or so years and had 'em all running, my coils were not incorrectly assembled by a previous owner, I did it myself, and I was too ignorant to post up my problem here and only solved it by borrowing a mint set of stock coils from my buddy for comparison/testing, after installing my entire collection of spare coils WRONG, and thinking they were all somehow bad.

[scottly]

Don't forget that you now have the added option of turning your headlight on or off!

[madmtnmotors]

Well done Scott. 

I went back and looked at the pictures too, and I had a heck of a time spotting that, and that was after you told us what the issue was. Let that be a lesson to all that ask for guidance...

you can't take too many pictures! 

[scottly]

you can't take too many pictures! 

10+ Bits are cheap, and a picture is always worth a thousand words.

[DH]

You deserve a beer or two for that one sir. I raise my glass to you.

[NobleHops]

Scott, you kick ass. b1jackson, you do too, for hanging in there and sorting this out.

[b1jackson]

About 10kms of a flawless road test complete.  Ran it through all the gears and had it up over 60 mph a few times.  Pulls pretty dang strong!  I was impressed with the power of it.  Idle seemed to smooth out when it warmed up. 

I need to fix my carb bowl gasket on # 1 as when I put it on the side stand, it weeps out.  I think the PO put a kit in the carbs and perhaps used a cheaper quality gasket that isn't sealing correctly. 

I've also got fresh oil in it with a small dose of seafoam to hopefully solve a fouling plug issue that the PO mentioned.  I'll do a few more short runs with it before changing out the oil.  I know there are sceptical folks on seafoam, but I've always had good luck with it.