Uh oh, losing power above 5K

Just as general info regarding analysis of coil performance, the dual outlet coil terminals do not have a specified polarity. It doesn't matter which terminal is supplied with battery voltage so long as the other terminal goes to the set of points triggering that particular coil.

My over-simplified understanding is as follows:

While the points are closed --
Battery positive voltage enters the primary winding and exits the primary winding to ground through the closed points, which completes the circuit. (i.e., battery voltage through primary winding to ground). The typical 3 ohm measurement is between coil terminals. During this time some electrical magic happens whereby a "magnetic field" is created in the primary windings, and this magnetic field just sits there in the primary windings while the points remain closed. The primary winding is situated near to but doesn't touch the secondary winding (at least not supposed to touch), and the secondary winding just sits there calmly waiting for something to happen. And happen, it does

When the points open -- the current quits flowing through the primary winding because it's no longer able to reach ground through the open points. So the magnetic field sitting in the primary winding "collapses" (dies - terminates - ends - whatever), and now the voodoo really happens. "Magnetic flux" "induces" high voltage in the secondary winding. Such high voltage circulates through the plug wires including jumps across the spark-plug tips. I envision high voltage leaving the secondary winding through one plug wire, going into the top of one plug and sparking down across the plug tip to ground (the head), going on across the head to the other plug threads grounded in the head, jumping up from the plug threads "backwards" across the plug tip to the plug top, and on through the cap and plug wire back into the coil secondary winding. Thus, the high voltage completes a loop from one end of the coil > plug wire > plug cap > plug top > arc across to plug thread > across head > other plug thread > arc across to plug top > cap > other plug wire > coil. And all this happens pretty quick.

Now -- after they have recovered -- loudhvx, steell & co. may please rescue me from this mess. :laugh:

Given good continuity from the points to the coil, more suspicion is cast on continuity from battery to coil.

Don't dispair. It may wind up being something real simple such as a faulty connector somewhere in the wiring between battery positive terminal and coil (as others have suggested).

Good Luck!

very well put. i remeber reading that the temrinals on the coils do not matter which one is which. They can be used as either the points connection or the red/yellow wire. i assume the red/yellow wire is the power. since the power wire separates just before the coils, how can one be bad? ill test shortly

For example, the red/yellow wire pictured below looks just fine.



But the red/yellow is in fact internally frayed or broken somewhere inside underneath the insulation because it has intermittant continuity.

Manipulating the red/yellow wire while testing its continuity with an ohmmeter causes the ohmmeter to jump around. This defect results in intermittent power to the coil primary winding.

The coil itself is good and measures 3 ohms (when the red/yellow wire is held in position allowing continuity).

Am guessing such internal wire issue is less common than a faulty connector issue. But it happened to this one. (New Dyna coils from Z1E resolved the problem, as the dual outlet connector had full battery voltage).

Awaiting results of the further testing.

further testing updates

Okay I think I have solved the problem.

If you remember before, I had it running on all 4 cylinders up to about 5k, then it became 4k and so on. Then after a while I was running on 2 cylinders.

So today I took out the #4 spark plug and it did not spark. So I moved that green wire to the other coil. And the black wire from the other coil to this coil. Cranked it over and low and behold, it sparked. Now this leaves me fairly positive that it is definately a coil problem

I'm just brainstorming that maybe my scattered test results were due to a coil GOING bad and giving me bad readings. So it worked sometimes and sometimes not. I think it finally is dead.

Does this all sound reasonable? Thanks for all the help!

Regarding wires from points to coils --

Left-side points trigger whichever coil fires the two outside plugs.
Right-side points trigger whichever coil fires the two inside plugs.
This applies regardless of wire-color and regardless of physical location of coils on the bike.

If a coil successfully fires 2 plugs, the coil is presumably good, with trigger wire from the points being okay. The other coil, if good, should do likewise.

If the same good coil fails to fire the other 2 plugs with the other trigger wire from the other points, the fault could be in the trigger wire, points, plug, or other ignition component.

Good Luck!

Yup thats what happened. One coil would not fire the black wire. So I switched it over to the other coil, and it fired those plugs! I was looking at z1enterprises for th e coils. Which dyna set should I get? The 3.0 ohm ones? Does it matter what rating for my application? I just have the 4-1 with points and condenser still

Wondering about any progress?

Meanwhile -- is the battery unquestionably good. And is the groundwire from the negative terminal solidly connected to the engine/frame. A poorly connected battery ground can cause ignition problems, and might have vibrated loose.

Also -- have the valve clearances been checked? The compression test alone is not enough.

Am not convinced either coil is defective, but new Dynas certainly won't harm anything and are likely to produce better spark than the old oem coils. And would concur with others about also replacing the points ignition with a Dyna S electronic ignition ( I would do first, and test engine performance before replacing the coils -- as a basis for comparison). While replacing, would also get new Dyna solid core plug wires, which come with the caps already attached.

Regarding which Dyna coils, offhand I was thinking the green 3 ohm coils, but recall somewhere mentioned in this thread about 4 ohm. Suggest double-check factory specs and discuss with Z1E to confirm proper application. When doubtful, it's better to go with higher ohm selection than risk being too low.

Good Luck!

hey thanks for checkin in. I ordered the 3.0ohm coils. They are matched for an upgrade to a dyna-s in the future. The wiring and grounds all look excellent, so I'm fairly certain that is the problem. And like you said, it won't harm anything to get new dyna's. Those accel coils are a little suspect and also accel has been beyond unhelpful and i will never go back to them.

At risk of redundancy, would also double-check integrity of all fuses and for sound fitment in the fuse holders -- still thinking maybe something vibrated loose. (Am recalling the history of such eratic test results being all over the place.)

Edit: Oops. Already covered.

Part should be here today. Now that I have wires here and there i need a little reminder to be positive. Which signal wire controls which coil? As in which cylinders do the black wire fire, and which do the green wire go to?

Also can plug wire placement be for either cylinder 2 OR 3 for example. Meaning does it matter which plug wire from the same coil goes to to cyl 2 or for cyl 3?

freebyrd24 wrote:

... Which signal wire controls which coil?
Also can plug wire placement be for either cylinder 2 OR 3 for example. Meaning does it matter which plug wire from the same coil goes to to cyl 2 or for cyl 3?

From square one --

As known, there are of course two separate ignition coils.
Regardless of their mounting location on the bike, one of the coils fires both outside sparkplugs #1/4 (either wire to either plug). And the other coil fires both inside sparkplugs #2/3 (either wire to either plug).

A coil doesn't know which two plugs it's firing. It only knows it's firing two plugs. It's our responsibility to assure (1) the plugwires from one of the coils is going to the outside plugs #1/4, and (2) the plugwires from the other coil is going to the inside plugs #2/3.

Under the points cover, there are two DynaS modules, one being located on the left-hand side, and another located on the right-hand side. The wire from the left-hand module (regardless of color) connects to the coil firing outside sparkplugs #1/4. The wire from the right-hand module (regardless of color) connects to the coil firing inside sparkplugs #2/3. These wiring connections are the same as in the old replaced wiring from points to coils.

Stated another way, regardless of the wire colors involved, the left-hand DynaS module triggers (signals) whichever coil is firing the outside sparkplugs #1/4. And the right-hand DynaS module triggers (signals) whichever coil is firing the inside sparkplugs #2/3.

A DynaS module doesn't know which coil is receiving it's signal, so it's our responsibility to assure the wire from the respective module connects to the proper coil (left module to coil firing #1/4, and right module to coil firing #2/3).

The third wire on the DynaS is for providing positive battery voltage to the DynaS when the ignition switch is turned to the ON position. I elected to tap this third wire into the bike's red/yellow wire underneath the fuel tank ahead of the dual connector feeding the coils. Dyna may furnish a plastic wire-tap-in piece for this purpose, but the better practice is to carefully solder the tap-in joint (without using the plastic piece at all).

Good Luck!

perfect! just what i needed to know! thank you!