Coils troubleshooting - still can't get engine started

[Guest]

I'm back at trying to resurrect the 650GL (as a first-timer). After cleaning the carbs, re-assembling them, and swapping some valve shims, I'm now trying to get the bike started and hoping someone could help troubleshoot.

Here is where things stand.

1. New battery and plugs, starter switch works, and my test light shows power is getting to all 4 coil terminals.

2. (Based on a spark plug tester) I'm getting spark to 2&3, but not 1&4. Putting wire 2 on plug 1 I do get spark; same thing happens when I put wire 3 on plug 4. This made me wonder if the right coil (serves 1 & 4) was bad.

3. Resistance for left coil measures 4.2 across terminals and 22.23 from wire to wire. Right coil measures 4.4 across the terminals and 19.83 from wire to wire. This all seems reasonable from what I can tell.

4. I'm using a small external fuel tank (primary tank still needs to be cleaned). In order to make sure fuel was reaching the carbs, I opened up the drain screw on carb 1 and plenty of fuel drained out.

5. For what it's worth, my motor was very hard to turn with plugs in for doing valve clearances (I took them out, and it turned easily). I'm hoping this means nothing is seized, and I have compression.

Where would you go next with this?

Thanks!
Drew

[tobaccorancher]

Are the "wire to wire" measurements actually in kiloOhms? If so, your coil impedances seem to be ok. Do you have an ignitor or points and condenser?

[tom203]

There’s a 4 wire connector that runs from ignitor up to ignition coils…find it and clean it carefully . It’s just under seat on right in a mounting bracket.

[Redman]

Have you ohm checked the caps? THey can and do go bad, much higher than the 5K they are suppose to be. (assuming stock type coils and caps).

Also, tell us more about the ohm readings, is suspision that you havent stated ohms nor KiloOhms.
ALso, I assume trhat when you say "wire to wire" you mean with the caps off (because that should be about 20K).

.

[Guest]

Thanks for all of the ideas. I'll look at these tomorrow. The plug caps look to be in rough shape for sure.

[tom203]

With plug caps off, wire to wire should be about12 kohms. Plug caps vary….newer ones about 5 kohms each, but old stock ones could be10 kohms each.