Cylinders 2 and 3 no spark

[Guest]

I got the part I needed to get my old girl running again since my fall in December (Thanks again Tom MLC) and she started right up. I checked everything out and all was looking good - did a few laps around the blocks, etc, so I decided to go on a short ride and then trouble started.

I had done about 20 miles and started to climb a hill and suddenly a loss of power, like the old days when my regulator and/or stator quit.

But unlike the old days my battery is fully charged and I have no trouble restarting the bike. And the gauges are nice and bright, also a sign the stator is working fine from past experience.

This time it seems the #2 and #3 cylinder are not firing. I notice no change in revs when I remove these two plug wires. Also I get no spark when I put the #2 and #3 wires to the block. So does this mean a possible coil problem?

Not sure where to look so any suggestions, please?

Thanks,

-Bob

[ryonker]

It's not likely your coil. One coil fires 1 & 3, the other fires 2 & 4.

It could be;

1. Bad plug wires (might need trimming)

2. Did you check the spark with just the wires, or with the plugs attached?

I can't think of anything else right now. Someone more experienced than I will chime in soon.

Good luck!

Rick

[chef1366]

Sorry but it is likely your coil.
They fire 1&4-2&3

[ryonker]

Sorry but it is likely your coil.
They fire 1&4-2&3

Oops

See I told you someone smarter than I would chime in. This is what happens when I take a break during the winter.

Thanks Chef!

Rick

[littleroot]

Sorry but it is likely your coil.
They fire 1&4-2&3

OK, great. How should I test?

Many thanks

[850 Combat]

Does it have points, or is it an electronic ignition?

The last one I messed with with that problem, I was able to switch the low tension leads on the coil from the points to the other coil, and the plug wires were long enough to switch too. Boom, now it still ran on 1 and 4, but with the other coil, and 2 and 3 were still dead, proving that both coils were good. That will at least let you know if it is the coil, or if it is upstream of the coil.

In my case, it was the condenser.

[chef1366]

Swap the coils and see if the problem moves to 1&4.
I'm not smarter than you. Everyone has a brain fart sometimes!

[SqDancerLynn1]

Before doing a lot of part swapping make sure you have 12 v on both the coils

[rustybronco]

Before doing a lot of part swapping make sure you have 12 v on both the coils

+1

also, if you have a volt Ohm meter, check the resistance of the primary side of the coil; it should read around 3 Ohm's. then check the secondary side of the coil, from plug cap to plug cap; you should get somewhere between 21K (21,00) and 35K Ohm's.

if it all is well with those readings then swap the coils as Bill suggested. if the problem moves with the coils you have a bad coil. if the problem stays with cylinders 2 & 3, you might possibly have a problem with your igniter.

[littleroot]

Sorry but it is likely your coil.
They fire 1&4-2&3

So embarrasing: guys, I accidently damaged the wire when put the tank on in my haste to take her for a ride when I got her running. How it ran fine for 20 miles I have no idea. I have made repairs and seems fine but I have to take her out for some test miles as soon as I am free from family duties.

Thanks to everyone who gave advice - it helped me look in the right place when I got back to the bike!

-Bob

[chef1366]

Cool beans.

[bwringer]

*sniffle*

I just love a happy ending!

[littleroot]

Ya'll are the best!