Stick Coils

[gaillarry]

Just did a mod to my 1990 Kawasaki Concours. Removed the stock ignition coils and replaced the whole setup with stick coils from a sports bike. Stick coils have the coil built into spark plug cap and provide better spark..




Cost me $60 for a set of 4 from fleabay. Anyone tried this on an XS ?

[natemoen]

How tall are they? What is the output of the coils and what is the ohm rating of the coils?

[DAVINCI]

Did you parallel them for a wasted spark system? If so, your TCI may not like that.
Looking closer, it appears they are series connected.
What do you mean by 'better spark'?

I type slower than Nate, but I see he's going down the same path as me...

[crazy steve]

Yeah, you need to match the electrical load so you don't let the factory smoke out of your ignition box...

A lot of these newer, smaller coils also need 'dwell control' built into the ignition, something the early ignitions usually lack. Without that, these coils will quickly burn out....

[natemoen]

I type slower than Nate, but I see he's going down the same path as me...

You are more knowledgeable though and go more in depth.

It seems like a somewhat interesting idea and would clean up some of the crap up there between the frame rails if it would work.

[Lonerider62]

I'm not so sure that almost all manufacturers are goig that route to make a "hotter" spark as to keep the travel of that high voltage jolt travel the least distance. In the old method of mounting the coil(s) in one spot then sending the spark a long distance to the plug, there is a lot of area that is succeptable to having that high voltage jump to any grounded part. With the new setups it's only a low voltage that neds to be sent long distances then converted to a high voltage. This also keeps noise from the spark down to a minimum. My own coils on my FZ1 have a primary resistance of 1.19-1.61 OHM and a secondary resistance of 8.5-11.5 K ohm. Now, that said, on the FZ1, each cylinder has it's own coil, not a twinned setup like on the XS and each one gets it's primary signal individually. It would take a lot of figuring to see exactly how they'd have to be wired to work propperly and whether or not it would overdrive either the ignition unit or the coils. I would like to see if it could be done however, my FZ1 coils are about 7 inches long and it would take some shopping to find a coil that was the right size and have the correct electrical properties

[DAVINCI]

The XS's use a 3ohm coil setup. I think the question was, what do the new stick coils ohm out at? If they ohm out at let's say. 1.5 ohms, then you could series them for a 3ohm total and use them in the XS wasted spark system, HOWEVER, if they ohm out at let's say 3ohms and you parallel them, the final resistance is IIRC, close to half (pure resistance, i know, this is inductive) and this could cause trouble with your XS TCI.

[gaillarry]

The stick coils I got are 6" long, from a GSXR. They are 1.5 ohms each. I'll find a used TCI on fleabay just in case it blows. I'm waiting on another set of stick coils from fleabay. Here's the wiring diagram for the Kawasaki.

[natemoen]

Sounds like it might be right.....

Don't know if it makes a difference but the XS uses a common line on one side of the coils.

[crazy steve]

I'll repeat this... if converting to later stick or mini coils, even if the coils measure the same ohms, you have to verify if they are designed to operate on a 'dwell control' type ignition. If they are (and almost all coil-on-plug ignitions now feature this) and your ignition doesn't have this, the coils will burn up...

What happens is the dwell control ignitions limits the duration of the 'power pulse' (that fires the plug) to a maximum time (usually less than 30 ms). At high rpms, it's not needed as the firing pulses are short. But at low/mid rpms without the dwell control, the pulses will be longer and the coil will have time to saturate. Once it reaches saturation, current will go up quickly and the coil will start heating. Because of their compact size and lighter-gauge wire, these coils can't take this for long.

I found this out when looking for new coils for one of my XSs; Dyna makes a 'mini-coil' (same ohms, same mounting, more compact) that points the plug wires straight back just like the OEM coils, so it looked like a perfect solution. But I was informed by their tech that without this dwell control built-in to the ignition, they would fail quickly...

[gaillarry]

Now that I'm better informed, I'll stay with the stock setup.

[jwhughes3]

I always appreciate

Those of you who experiment and try stuff " out of the box "....

In the long run its this that will keep us on the road longest.

John

[James England]

Loads of cars have this setup, don't they? I'm not sure they are known for their reliability though...

[Lonerider62]

Steve is correct about the dwell and in this case, what seems like it should work from a simple impedance stand point may not last very long in the end. The new electronic ignitions can do a lot more when it comes to delivering a good spark at exactly the right time than our older systems could and part of that is a shorter dwell than the older systems required.

[crazy steve]

The big advantage to a coil-on-plug ignition is they can 'tune' the coil for a much better spark at high rpm without having to worry about saturation at low speeds. A conventional 'multi-plug' coil, because it has to fire more often, has more trouble producing a big spark. But to avoid a large, bulky coil that would be needed to operate at all rpm ranges, they use dwell control to limit the time the coil is energized to the same amount as when running at high rpm.

The XS ignition system isn't all that bad; you're only firing two plugs, unlike the older cars where a single coil would be firing all the plugs. Many of the newer cars also use the 'wasted spark' system, with one coil per pair of cylinders. But dwell control would be a nice upgrade, then you could use a better coil. I'm sure you could get at least close to the performance of a coil-on-plug system if that were available for these bikes...