Topic: I need help with my electrical system

[Bacon550]

Ok so I bought a 77 cb550k on a whim.  It was running 6months prior to when I bought it.  Then it sat for 6 months and I brought it home.  I had very weak spark when I first tried to start her.  Then she lost all spark on all cylinders.  A friend told me coils went bad so I now have $120 dyna 5ohm coils and still no spark.  Needless to say that friend doesn't help with my bike anymore.  I've read over the FAQ and tips and tricks and did a search but I can't figure out where to start trouble shooting my problem.  If anyone would be willing to guide me threw trouble shooting this aggravating please do my sanity depends on it.

[Elan]

First, whats the story with your battery? holds a charge? headlight bright?
Do you have a wiring diagram?

I would start by testing All the coil wiring, one wire at a time.

[heyitsrama]

I'm currently attempting to troubleshoot my 500 as well for no spark on one set of coils  , although I modded one of the older ones with new coils. That specific coil does not produce spark..
I was informed in another thread to look at the condensers, but have not figured out a way to test them. (they should be fine because I'm getting weak spark on #2)
How have you attempted to troubleshoot this issue?

[Bacon550]

Battery is a year old.  Holds a charge lights are bright although I have the headlamp fuse removed to prolong battery life while I work on it.  Right now I have 11.48 volts at the battery and 9.41 at the 1-4 points.

[Elan]

start with your switch and key to on, check the black//white wires to the coils with a tester, do you have power?

[Bacon550]

start with your switch and key to on, check the black//white wires to the coils with a tester, do you have power?

.
I have 9 volts when I test the black and white wire ant the female bullet connector.

[Elan]

I would follow this test to check your points...

http://forums.sohc4.net/index.php?topic=107498.0

[Bacon550]

Ok when I bridge the points i get spark out the plug.  But nothing when I turn my starter over.  Does that mean my points aren't opening/closing like they should?

[Elan]

Ok when I bridge the points i get spark out the plug.  But nothing when I turn my starter over.  Does that mean my points aren't opening/closing like they should?

Sounds like it, have you set the proper gap? are the points original? Im not too familiar on testing the capacitors, maybe someone can chime in.

  Maybe a good time to pair a nice digital ignition with those coils?

[Bacon550]

I don't know how to set the gap properly.  The manual I have confuses me.  The pictures are to dark to see.  I don't know if they are original or not.  They look really clean.  I was gonna buy a honda man unit to go with the points.  I've read a lot of bad things about the electronic system here.

[Elan]

Do a search on here for how to set points. There should be a detailed follow through.  Sounds like thats your problem.  You may need to replace them if they are too far gone.

I love my electronic pamco unit. THe hondaman one is great too, but I think you still need to be able to set up your points.

[Bacon550]

Ok think I got it.  My friend set the points gap while they where closed.  Got spark now and it wanted to turn over but I drained the battery to much for it to fire up.  So guess its time to charge and start again tomorrow.  But found a new problem.  Carbs 1 and 2 are leaking out the float bowl gasket and idle screw.  So I guess new gaskets are in order.

[Elan]

Make sure your shut off valves in the carbs aren't clogged. Lots if times rust from the tank holds them open and fuel goes everywhere. Also the the floats are set correctly. Good luck

[bollingball]

Battery is a year old.  Holds a charge lights are bright although I have the headlamp fuse removed to prolong battery life while I work on it.  Right now I have 11.48 volts at the battery and 9.41 at the 1-4 points.

11.48v is not good. Disconnect it from the bike and charge it over night then take it off the charger. Let it rest about 2 hrs. then check the voltage you want at least 12.6v If your battery can be refilled then keep an eye on the level. Plus you are loosing a lot of voltage at the points go over all the connections in the circuit. Don't know on the 550 but on my 750 there is a connection for the points behind the rear brake light spring that gets over looked so clean it good You want bright and tight connections though out the bike.
Ken