Topic: 2/3 plugs not firing...HELP

[seattle550k]

Hello, new member here. 

So, here is the story.  I bought a '77 550k from a guy while he was "half way" through a café racer rebuild.  Turns out there was a lot more work to be done than advertised so I started going to work.  I changed the rear shocks, put in a new regulator/rectifier, changed out the exhaust to a mac 4-1, put new sprockets and chain, adjusted the timing plate and points and various aesthetic changes.  Everything ran fine and I was on my way to Backfire Moto last week when the bike sputtered out along the way.

I checked the fuel and all is running and flowing fine.  Next to electrical, running through the checks and this is what I found.

All the plugs are getting a good spark when checked on wires 1 and 4.  2 and 3 are not getting a spark to any of the plugs. 

I'm not sure where to turn from here.  Any help is greatly appreciated and welcomed. Safe trails and happy riding.

[surveywaters]

You could start by unplugging all the spark plugs, swapping the leads at the coils which come from the points, then turn it over and see if 2/3 spark. This will tell you if it's the coil. If it's not the coil, the points are fouled.

[rb550four]

Be sure and check that all the wires to the coil are still plugged together tightly, Blues ,yellows  black and whites at coil, yellow and blues  near the battery where the harness connects with the brake light. sometimes wires feel all the way plugged in when they aren't, could be as simple as a loose connection.

[flybox1]

if all connections are good....coil test directions are here
http://forums.sohc4.net/index.php?topic=5752.0

[seattle550k]

Thank you for the knowledge and insight. I'll start tinkering and let you know what the outcome is. 

[Vinhead1957]

 Check the yellow wire under your points cover and make sure it is not grounded or loose at the points connection

[mono]

I blew a NEW condenser the other day and it took me 2 weeks to figure it out.  swap it out and see what happens.  It was the last thing I checked lol.

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[mono]

I guess you know you're getting old when "the other day" was like a month ago... Lol

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[Bankerdanny]

When I had problems with my 1-4 firing intermittently it was a loose wire where the condenser attached to the points.

You could try swapping the condensers and see if the problem transfers to the 1-4's.