Topic: '77 550K spark/coil issues

[youngerthanmybike]

I have a '77 CB550K that has about 32k on it. I just finished rebuilding the engine: cylinder hone, 650 camshaft and mild porting. So, I now have my bike put back together after the engine rebuild and I'm trying to get to the point that I can have it stay running to set the timing and and play with the carbs a bit. But I'm having issues.

I got it fired up without too many issues, but it was running really rough. I realized I wasn't sure which coils and wires went to which plugs, so once I straightened that out, I realized that my #1 & #4 header pipes are cold. I backtracked and made sure they were not getting spark by checking it with the plug out and against the engine block. I then went to the coils.

PO replaced the plug wires with some 8mm Taylor Silcon wires. I'm not sure if these are suppression or copper cored or not, I didn't pull them apart to check. There is no threaded connection, they appear to just be cut, spliced and taped. I don't know if these are the problem or not.

My understanding is that the left coil is to go with plugs 1 & 4, and the right coil is to go with 2 & 3. Well, the PO cut the plug wires too short for this to work, so the blue and yellow power supply wires going into the coils have been switched in order to make the plug wires work.

I'm not sure if it is the coil or not, but here is my thinking on why it is. With my multimeter in hand and the ignition switch and key ON, I got a reading of 12.XXv at the battery. At the wire connections of the black/white striped wires, I also got a reading of 12.XX. At the rear of each coil the reading was also 12.XX. At the blue and yellow wires leaving the ignition coils, I got respective readings of 11.XX and 0.00. That's why I think my coil is bad.

Questions:
#1- Am I missing something in my method of testing my coils or does my method make sense?
#2- Given the plug wires I have, should they be replaced?
#3- I assume my options for new coils are: used, new chinese replacements, or Dyna 5ohm. Pros/cons to each?
#4- Where does a Hondaman ignition module fit into this equation?
#5- Anything else I'm missing?

Thanks in advance-

[speedy gonzalais]

My understanding is that the left coil is to go with plugs 1 & 4, and the right coil is to go with 2 & 3

My 650 is left 1 & 3 and right does 2 & 4 dont no if the 550 is the same prob is.

[ieism]

I think you're right. From what I remember the left coil goes to 1 & 4 on a 550 too.

[TwoTired]

At the blue and yellow wires leaving the ignition coils, I got respective readings of 11.XX and 0.00. That's why I think my coil is bad.

When the points close, they complete the circuit so current can flow in the coil primary.  Usually one set of points is closed at a time.  Therefore, it is normal for the Blue or Yellow wires to read near battery voltage for one and 0V for the other (because that set of points is closed).  If you rotate the crank 180 degree, the indications on the Blue and Yellow wires will be reversed.

It's unusual for a coil to go bad.  However, tampering with the ignition wires can make this happen, as will bullet holes in the coil body.

Probably a good idea to clean the point contacts to make sure there is no film that will prevent current flow (which will keep the coils from charging).

Your plug wires should be solid core.  Your spark plug caps should have either 5KΩ or 10KΩ resistance, and your spark plug should not be resistor type (R in the number).  If you insist on resistor plugs, then use plug caps without resistance built in.  If you insist on resistance wire - good luck!

Check which wire comes from the 1-4 points. It should go to the coil feeding the 1-4 cylinder spark plugs.

Cheers,

[youngerthanmybike]

 
If you rotate the crank 180 degree, the indications on the Blue and Yellow wires will be reversed.



Check which wire comes from the 1-4 points. It should go to the coil feeding the 1-4 cylinder spark plugs.

I'll check the readings on the wires and get back to ya after dinner-
Which side of the points is 1-4, and which is 2-3?

Got some good info here: http://forums.sohc4.net/index.php?topic=29529.0
but I'm still stuck.

Here's the coils I was looking at-
Dyna 5ohm: http://www.z1enterprises.com/detail.aspx?ID=1307
Cheapo: http://www.z1enterprises.com/detail.aspx?ID=2857

[youngerthanmybike]

Okay, so you were right TT. Not that I doubted you, but I did want to confirm your statements. I do have voltage at the output of each coil, I just have to have the crank in the right spot. Oh, and uh, once I got out there, I realized that the points are labeled 1-4 and 2-3 

I think the PO, or maybe it was me....., swapped the coils left to right, so all I have to do is swap them back in order for the wiring to be correct. Then it will all make sense.

Looks like I will be buying new plug wires. Can I just splice them together or do I need to use those NGK wire connectors?

Where the power feeds enter and leave the coils, the plastic coating on the wires has worn so that some of the wire is exposed. Is there any way to re-coat that or protect it somehow?

[TwoTired]

There is over 10K volts on the ignition wires, simple electrical tape is NOT rated for that kind of use.  Use the NGK splices if you can get them.  RTV is good for HV use, but it doesn't have much mechanical strength to hold the insulation parts together. Maybe RTV under shrink wrap and the shrink wrap tie wrapped to the insulation?  Just a suggestion.

For the exposed input wiring, you can dobb some Liquid Vinyl on them to cover the copper conductors.  It's water proof after it cures.

Cheers,

[youngerthanmybike]

Okay, now I'm getting somewhere.

I want to pick up new wires to splice in, how do I know if they are "resistance" wires or not? Most wires I looked at simply said "suppression" or silicone core.

When you said "spark plug caps," did you mean the actual rubber cap that snaps onto the plug or the entire wire unit with cap and wire?

You also said "solid core wire." Is that truly a solid wire at it's core, or is it stranded? If it's stranded, why is called solid core?

As I took mine apart, I noticed that the connector used in the splice looks mostly like a small nail. Can I use a nail? Or should I use a small piece of solid copper wire?

Thanks TT-

Oh, and what model car could I get solid core copper wires for from NAPA?

[TwoTired]

I want to pick up new wires to splice in, how do I know if they are "resistance" wires or not? Most wires I looked at simply said "suppression" or silicone core.

Those wires have carbon as part of the center conductor.  They will have a rating in ohms per foot from the manufacturer (if not the parts distributor).
Modern cars need these, so as not to blow up the computer in the car, and their spark voltages are 3 or 4 time higher than what the Honda coils can make.  Suppression wires have a finite useful life of about 5 years.

When you said "spark plug caps," did you mean the actual rubber cap that snaps onto the plug or the entire wire unit with cap and wire?

I'm not certain what's been adapted to your bike.
The stock bike had NGK hard plastic boots (with rubber seals) and a resistor inside it.

You also said "solid core wire." Is that truly a solid wire at it's core, or is it stranded? If it's stranded, why is called solid core?

It's actually stranded.  When compared to suppression core ignition wires, it behaves as solid core copper.  Ohms/ft is like .001, about.

As I took mine apart, I noticed that the connector used in the splice looks mostly like a small nail. Can I use a nail? Or should I use a small piece of solid copper wire?

In theory, you should use the same type of metal as the core of the wire.  But, if you can (and should) keep the core splice isolated from water or the atmosphere, corrosive effects and galvanic corrosion factors should be minimal with your standard steel nail.  This approach is for shade tree mechanics, not professionals, or production type applications.  It often works.  But, it ain't elegant!

Oh, and what model car could I get solid core copper wires for from NAPA?

The stock wires were 7mm stranded core (about 5-7 strands).   I don't know if NAPA carries that or has to order it.   Then there are the plug caps to consider... There's two kinds, one with deeper reach.  Honda or other MC shops should still sell them.  I don't know of any autos that used these.

I'm assuming you want to restore to stock configuration.  There are other component selections that will work if you just want something that is easy/locally available.  But, I don't know what NAPA has in standard stock.

Cheers,

[youngerthanmybike]

Actually, at this point I think I'd prefer easy and locally available over restoring it to the stock configuration. This has turned into way more work than I anticipated. Not the entire bike, just the ignition system.

I just took all the wires apart to see what I had to work with. It looks like I don't have much to work with. Each coil had only 2-3" of wire sticking out of it. On two of the four wires, it was completely shot back to the coil. One of them was sketchy, and one was good. This being the case, I decided to try and cut the coil open to replace the entire wire. I cut it back with my dremel and exposed both of the wire channels on each coil. I then secured a connector, or stud if you will, at the base of the wire channel. I'll secure each wire individually into place and then rebuild the case of the coil with epoxy. Now all I have to do is come up with some wires and boots/caps.

I'm thinking about just having my local bike shop order another set of the Taylor 8mm wires I had. I won't have them til Monday, but I'll have them. They were copper core, but all but one had gotten to be too short. Any other quick and easy solutions out there?