Triumphrat

kawtoy

73 T140V. Bike was running, then not, then running, now not. It was getting hard to start. Messed with timing and screwed it up. Fixed that and got it running. It would take about 3 kicks, then 6 kicks and now no kicks. I am not getting a spark at all. I hooked up a multimeter to the plug wires and no juice. I can't make head nor tales on the wiring schematics. Battery is fully charged. Can someone walk me thru the places to check for voltage? You know..power should be here but not here. Power should be here when kicked over and not here. I really want to get this bike back running so I can show off the new paint. Thanks

Bonnevillian

Did ya do the WD-40-in-the-ignition-switch-and- turning-it-off-and-on-a-ton-of-times trick?

I had to do that to mine as I was getting intermittent connection. Works everytime now....

OzBloke

Kawtoy,

Check fuse.

Put your postive/red lead from the multimeter (on 20V DC Range) on the battery +ve. With ignition switch on, put your negative/black lead on the -ve of either coil. Can't remember if you have a Boyer, but you will get either 12V (points) or 6V, depending on your ignition type and which coil you chose.

If nothing there, you have a problem with ignition switch or kill switch. If the oil pressure warning lamp on the headshell (the red one) comes on when you turn ignition on, it's most likely the kill switch circuit.

Let us know how you go with this test, and we can go from there.

Pete

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kawtoy

I checked the coils and I am getting 12.5v at both + and - of each coil. Woo-Hoo or Ohh-Noo ?

OzBloke

Kawtoy,

12.5V at -ve is good. 12.5V at +ve means your points are open (not bad, just a bit more diagnosis..). Try the following.

Before you take things any further, are you sure you've got good fuel flow - ticklers work, and fuel spits out the little hole?

If so, here's the next stage of the electrical stuff:

1) take the plugs out.

2) take the points cover off

3) rotate the crankshaft slowly (using the kickstarter) until one set of points is definitely closed.

4) Ingnition on. Check the coil +ve terminal voltage on that side - should be 0V. If not - dirty or misadjusted points, or broken wire of connector between coil and points.

Alternative to above 4:

a) Plugs out

b) Ignition off. take the Black/yellow and black/white wires off the +ve terminals of the coils.

c) With multimeter on 200 Ohms range, one lead on Battery +ve and the other on the end of either (one at a time) black/yellow or black/white lead you just took off the coil.

d) slowly rotate crankshaft and at one point you should get <5ohms - note this will only be once in two revolutions of the crank.

If 1-4 OK or a-d OK, check the static timing. It's possible something has slipped or stuck in the mechanical advance plate behind your points plate.

Again. please let us know how you go....
Pete

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kawtoy

So I did some of the checks you guys mentioned. Everything you said to check was good. Still no spark though. I checked voltage at the points while rotating the engine and I get 12.3v at each point when it opens up. I also checked for voltage at the coils where the plug wires plug into. I get 12.3v at part of the rotation and 0 at the rest of the rotation. So what the heck should I try next? Thanks

OzBloke

Kawtoy,
Ignition switch is fine.

Sounds like the primary side of the coils is OK. Just reaffirm for me that the points side of each coil (+ve terminal) is going to 0V when the points are closed.

What sort of condition are your plugs in? are they black and wet, or black and dry, or new, or what? have you gapped them recently?

When checking for spark, do you have the plug in the lead, and resting on the fins of the head?

Measure the resistance of the plug lead end-to-end. If copper wire, it should read very low (<10ohms). If suppression type (carbon filament) could read as high as 10Kohms. Let us know this reading for both leads.

Then measure the resistance of the secondary side of each coil (IGNITION OFF!!!) - +ve terminal to where the plugs leads plug in to. Points wire should be off when you do this measurement.

There is logic to this......

Pete

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kawtoy

When points are closed I am getting about .07v, so close to 0. I put in new plugs and gapped them to .25. I hooked up a light bulb tester between my plug and plug wires. When I kick the bike over I only get a very faint light. I had to turn the lights out in the garage to even see it. I tried to hold the plugs against the engine case and see a spark but I didn't see any. If it was a faint as the light bulb then I wouldn't have been able to see it anyway. The battery is at 12.07v now. It was fully charged to about 13 before but it has drained a bit with me trying to get the bike going. Any more ideas? I would really like to have the bike ready to roll this weekend. ***** you Lucas!!!!!!!!!!!!!!!!!!

OzBloke

Kawtoy,

12.07V should be OK to get spark and start the engine, especially if you're measuring the volatge with the Ignition on. Could do with a top up though.

0.7V at coild +ve is good with points closed.

the light bulb is fairly useless in regard to testing the spark. The duration of the spark doesn't give the bulb filament time to warm up to glow. Same with a multimeter - doesn't have time to react and show the proper reading. However, it does indicate, from what you've said, that you are at least getting a voltage output from your coils.

I hope you meant you gapped them to 25 thousandths of an inch, not .25" . I usually set at 28 thou, or 0.7mm

The only other thing electrical that could be stopping it from running is the timing. You need to check your mechanical advance is not stuck on full advance, or the points plate hasn't slipped around. Do a static time setup and check.

Pete

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kawtoy

.25 inches would be a hell of a gap. Mine are set at 25 thou. I am really starting to hate British electrics. Should I take the points plate out and look at everything. How to make sure that the advance is not stuck? Thanks