Topic: No Spark Help please.... (CB550)

[NewKidOnTheBlock]

Hey guys first post, but theres a place for introductions.
Can't seem to figure out why I have no spark. I'm using a new battery reading at 12.1 and I'm getting 12.0 at the points. However when I take a spark plug out ground it to the engine and hit the starter nothing. Tried all cylinders just in case and nothing. Any help or advice would be much appreciated.
Motorcycle: 1974 cb550

[tfrasca]

Is it cranking over, just no spark at the plug?

[jtb]

Kill Switch?

[goldarrow]

Check your connections at the coils, ignition key, ignition points plate, inside headlight bucket?

[NewKidOnTheBlock]

1)Yes sir it is cranking but no spark.

2)Very possible the kill switch could be faulty. How would I check that?

3)I believe ignition key is hot, points are hot, and everything else I need direction to check.

(1st vehicle I've tinkered on that had both carbs and points. Also first bike I've worked on.)

[gloken]

1)Yes sir it is cranking but no spark.

2)Very possible the kill switch could be faulty. How would I check that?

3)I believe ignition key is hot, points are hot, and everything else I need direction to check.

(1st vehicle I've tinkered on that had both carbs and points. Also first bike I've worked on.)

Check the killswitch with a volt meter. Open up the casing and see if you have current across the switch. It's super simple, all it's doing is interrupting the voltage.

[NewKidOnTheBlock]

Will do that tomorrow and post back again! Should've thought that out, just getting frustrated, hopefully getting a spark will give me a moral booster!
Thanks to everyone who is contributing didn't think I'd get this much feedback so quickly. It's awesome!

[gloken]

I went through the spark debugging this summer on my own bike, it's not that bad once you get an idea of how the circuit works. You don't need to be GOOD with a volt meter, it's pretty easy.

You said that your plugs don't spark when you're holding them to the head, but do the points spark when you turn it over? For me, one of my many problems was just corroded points.

[NewKidOnTheBlock]

Ok guys so I checked what I believe to be the hots that lead to the coils. I checked the blue and yellow so right now it looks to be a kill switch problem, which I will begin looking into. But my cheap battery is draining fast so first going to grab a charger. Will post another update later today.

I just went outside to see if turning it over would produce a spark and no luck. Now I'm convinced it has to be the kill switch and if not I'll have to take a look at the replacement ignition switch I bought.

[NewKidOnTheBlock]

School is getting in the way of my build... or is my build getting in the way of school. Anyway had a chance to open up the kill switch, low and behold wires leading to it had come off their solder. Going to re-solder these then hopefully I'll be in business.
(when I opened it up looked as it someone else had been messing with it)

[NewKidOnTheBlock]

For those who stumble upon this same problem I used http://forums.sohc4.net/index.php?topic=80532.msg901194#msg901194
It is an awesome write up SohRon.

[CoachDoc]

Check to see if you have power at the ignition coils. If not there is a four way connector in the headlight bucket that brings switched power to the coils that often goes bad. Refer to the wiring diagrams others have sent you. Clean the connectors with emery paper for the males ends and a .22 or .17 caliber rifle bore cleaning brush for the female ends.