You must be friggin' kidding me... (coils)

[Guest]

So I completed the coil relay mod and found that the bike runs on only cylinders 1 and 4. I redid all the connections for the affected coil on the relay mod and am certain that they are solid.

This means I have a problem with the left-side coil. I want to test it, but according to some threads I searched here, both the primary connections and the high-tension connections (where the plug leads go) are EPOXIED IN PLACE!!

Is this true? If so, what kind of motorcycle manufacturer would design a system that can't be repaired with regular tools? Or am I missing something obvious? I tried to pull the plug leads out of the coil, and tied to unscrew them, but neither had any effect at all.

I guess I need to swap the coils but can't do that without removing the plug leads. How do I do that?

[mforbes]

The stock coil leads are epoxied. When my coils burned up, I replaced them with the Dyno Greens. Much better coil. Saved a lot of headaches. Plus you can change your leads from time to time. Higher voltage too over the stock one gives a better spark.

So I completed the coil relay mod and found that the bike runs on only cylinders 1 and 4. I redid all the connections for the affected coil on the relay mod and am certain that they are solid.

This means I have a problem with the left-side coil. I want to test it, but according to some threads I searched here, both the primary connections and the high-tension connections (where the plug leads go) are EPOXIED IN PLACE!!

Is this true? If so, what kind of motorcycle manufacturer would design a system that can't be repaired with regular tools? Or am I missing something obvious? I tried to pull the plug leads out of the coil, and tied to unscrew them, but neither had any effect at all.

I guess I need to swap the coils but can't do that without removing the plug leads. How do I do that?

[FiremanBob]

So if I buy the Dyna coils I can use regular spade connectors on the primary leads? And how exactly will the plug leads connect to the new coils?

And if I try to use the old coils, I understand that I would have to solder/epoxy the primary leads (as per BassCliff's excellent "Simple Coil Repair" article - yeah, simple if you're expert with a soldering iron). But I'm still stymied on the plug leads.

I never imagined a Japanese manufacturer would use such cheapskate engineering on one of its products.

Supposing I go for replacement coils, what is better, Dyna or Accel? What model number of each should I get, and where is the best (cheapest, fastest) place to buy them?

Thanks.

[mike_of_bbg]

Coils don't frequently go bad. They're just loops of wires. The HT leads are copper core and also don't usually go bad, except perhaps a little corrosion at the plug cap end. Hence the normal suggestion to cut about 1/4" of wire off when replacing plug caps. Were 2 and 3 firing before you did the coil relay mod?

have you checked the primary and secondary impedances of the coil? The primary should be about 3 ohms. The secondary is about 14k ohms for the coil itself, plus about 5k each for NGK or 10k each for stock plug caps. If it's very high take the plug caps off and re-check; the resistors in the plug caps go bad much more frequently than coils do.

I believe the Dyna green coils have screw terminals, so you'll just have to fabricate whatever you want as the connection type. There was a recent thread about how small the clearances are from those screws to the coil supports and the potential disastrous effects of such, so it's best to use some sort of insulator spacer.

[Matchless]

I never imagined a Japanese manufacturer would use such cheapskate engineering on one of its products.

Maybe the reason why a few of them need to be replaced after only 30 years!

[TheCafeKid]

Coils don't frequently go bad. They're just loops of wires. The HT leads are copper core and also don't usually go bad, except perhaps a little corrosion at the plug cap end. Hence the normal suggestion to cut about 1/4" of wire off when replacing plug caps. Were 2 and 3 firing before you did the coil relay mod?

have you checked the primary and secondary impedances of the coil? The primary should be about 3 ohms. The secondary is about 14k ohms for the coil itself, plus about 5k each for NGK or 10k each for stock plug caps. If it's very high take the plug caps off and re-check; the resistors in the plug caps go bad much more frequently than coils do.

I believe the Dyna green coils have screw terminals, so you'll just have to fabricate whatever you want as the connection type. There was a recent thread about how small the clearances are from those screws to the coil supports and the potential disastrous effects of such, so it's best to use some sort of insulator spacer.

Indeed those spaces become really really tight on some models (the 650 comes to mind) so some sort of insulation isn't just recommended it's downright necessary. Once we added in the connectors and assured everything worked I used some brush on liquid electrical tape (handy stuff btw)

I'm probably wrong but I thought the HT leads were actually SS cores? Not that it matters much as neither is particularly subject to massive corrosion given the situation...

[SqDancerLynn1]

Do you actually have 12 volts on the coil ???

[FiremanBob]

Thanks for the check, Lynn. Yes, I do have 12V to the coil, having checked the good coil on both output terminals of the relay. Unless the primary wire between the relay and the coil is broken, but then I'm not equipped to re-solder and epoxy a replacement.

[koolaid_kid]

Josh, the HT wires I have worked with on bikes were all copper based, not SS.
FiremanBob, the Dyna coils (and the Accel if you can find them) are screw-in threaded terminals, like everyone else uses (my KZ and GPz, for example). I have read that the OEM coils are also screw-in but are epoxied also.
AFA replacement wires, you can use automotive wires if you wish. They are "normally" suppression wires, so you would use the spark plug caps that came with them. And the spark plugs will need the screw-on tip they come with, instead of removing them like you do for the NGK caps. I went with the Dynatek wires, they were only around $18 for a new set.
And if you are getting 12V to the coil it is not your relay.

[FiremanBob]

Thanks. Update as of now:

I proved that the coil is getting 12V by testing at the relay output and then testing the wire from the relay to the coil. To do this, I had to chip off the epoxy around the terminal. The 12V pos terminal at the coil is a small tongue with a hole in it (sized for 18 ga wire). About 3mm of wire end goes into the hole and then is soldered together. I'll try BassCliff's method tomorrow for that, but am pessimistic because I suck at soldering.

So if the coil is getting power, the problem is either the coil itself or the ground wire. I tested the harness side of the black ground wire from the coil, and had no continuity to the battery negative. So I guess that wire is bad somewhere back in the harness. I plan to run another ground wire straight from the coil to a frame ground bolt.

At this point I have both primary wires removed from the coil and am waiting for the store to open so I can buy parts required to make the connections. The next phase of the saga will be my attempt to solder the new wires onto the coil primary terminals.

[koolaid_kid]

Ummm, I am confused. What ground?

[chef1366]

You have a power wire and a wire that comes from the igniter. No constant ground.
Switch the igniter wires on the coils and see if you can get the bad coil to fire.

[FiremanBob]

And how do I switch the igniter wires when they are soldered/epoxied to the coils?

And how do I test it then? Don't the igniters fire 180-degrees out of phase with each other?

Sorry for the dumb questions. Vehicle electrics are my weak spot.

[mike_of_bbg]

From the factory on the EI 8V 550s the coils should have had identical connectors, so it's usually not a big deal to swap them to see if the problem follows the coils or the leads. Once you swap them you can just lay the plug against the head in a dark garage to look for spark, or if you have enough lead swap the plug wires too. Sounds like your connectors may not be stock/unmolested. One of the stock coil connections is at the tip of my index finger in this photo:

[miked]

And how do I switch the igniter wires when they are soldered/epoxied to the coils?

you are referring to the wrong wires, switch the wires to the relays.

you are trying to take the wires that drive the non working coil and put them on the coil that is working to see if the problem is really with the coil (doubtful) or with the wiring.