Test coil spark plug wires

[Walmart Ninja]

I don’t have spark. Tested coil out of the machine and it looks like the numbers are ok. Tested plug caps and one is junk, and the others(not original) are between 9-12 kilo ohms. So those gotta go I assume and get 5k ohm caps.

I do have power to the coil from the battery. I don’t know how to check for ground, though.

When I removed the plug caps initially, they just pulled right off the wires. I had not seen that style before, where the cap screws into the plug wire. Anyway, the PO has some black adhesive crap in the ends of the plug wires - I assume to hold them on. I tried to stick a test light into the wire to see if I have juice, but it doesn’t light up. How can I test if the plug wires are any good?

Thanks

 

[hinksy]

Have a look at andy mechanic on youtube , he goes through testing coils and plugs

 

[Walmart Ninja]

That is the video used haha. He doesn’t test wires that I saw?

 

[Walmart Ninja]

I would be interested if anyone has instructions on how to remove the old spark plug cables and install aftermarket ones. Apparently you can cut them off and drill them out, but I was hoping for a little more instruction.

 

[Walmart Ninja]

Actually, screw it. After too much dinking around, I am replacing the coils and wires and caps. Is OEM the way to go? Any decent aftermarket kits? Thanks

 

[dirtdigger]

I dont think I would mess with trying to replace wires. There are many used parts on ebay and some new oem listings, plus new aftermarket at places like vintage cb750. Some oem honda parts suppliers still list a new oem set still available but yes they are pricey. You can also go with dyna ignition coils or do a complete ignition kit with coils

 

[Walmart Ninja]

Thanks digger. I am a little apprehensive about the aftermarket stuff as the prices are all over the place. I found a halfway decent deal on OEM but it's still a lot as you said. I'd also like to locate a good set of caps if you know of any.

 

[Walmart Ninja]

When I rebuilt my car, I had a real good idea of what was good and what was junk as far as parts go. I am totally in the dark with this project. So I appreciate any help with that

 

[dirtdigger]

I put dyna ignition on all of mine. I would look for a used set on ebay if you think the wires are bad. I personally have never had coils or wires go bad.

 

[Loki]

The plug leads on our coils are solid copper which is the reason for the 5K plug cap resistance, it's unlikely that the plug leads are faulty unless they have been mechanically damaged unlike the modern type which have glass fibre cores with carbon and sometimes spiral wound which do have a finite lifespan and need to be replaced periodically.
Back in the day when all plug leads were copper you could get cable connectors to enable a length of plug lead to be joined, these usually had a double ended screw which screwed into the ends of the two cables you wanted to join, normally it's at the end of the cable where the plug cap screws on that you get the failure so snipping off the last 1/2" or so then screwing in the plug cap again makes a quick and reliable repair.
I have found it more and more difficult to get non resistor spark plugs these days so if you can only get resistor ones deleting the 5K resistor plug caps will give a better spark.
When fitting new coils and trimming back the plug leads to fit it's a good idea to leave a bit of extra cable to allow for later trimming in the event of problems.
Coil testing is quite simple with a multimeter, put one test lead on the core (the part that bolts to the frame) and measure the resistance in ohms to the two leads from the points in turn these should have the same resistance reading, the ones I tested were about 6-7 ohms.
Not sure about testing the plug leads themselves though, couldn't get a reading on the spare coils I have, mind you that's not to say they're not junk as I haven't tried them on a bike!
Just watched a video and to test the plug leads you measure between the ends of the leads and should get a high resistance in the Kohm range.

Loki

 

[Walmart Ninja]

Thanks Loki. After much farting around, and eventually cutting the plug wires to maybe try epoxying new ones - and failing - I ordered repacement caps and coils

 

[Loki]

Makes sense as it looks like yours are in a bad way, I got an assortment of coils and plug caps with my bike as it was a basket case but also a new set of replacements from David Silver so just bolted them in and the bike ran so didn't give it any more thought!
I always try to fix things if possible but you need to know when to give up!

Loki

 

[Walmart Ninja]

Yes! Thanks again!