Ignition sensor, hall, vr

What are good or better than stock to run for coils?

notaduc wrote:

Do you mean the HEI ignitor setup?

Can I use the stock ignitor with the late ignition?

Yes, the HEI ignitor (and few extra components) is a substitue for the earlier, mechanical-advance ignition.

I don't think the early ignitor will work on the later, electronic-advance ignition. Either way you wouldn't have advance. You can, however put the entire older system onto a later bike. My friend put a mechanical-advance ignition (advancer, pickups, ignitor) to get a later gpz750 to run. THe coils were the same.

For either type (mechanical advance or e-advance factory ignition), the Dyna 2.2-ohm, gray coils are probably the best match.

Like this?

home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

notaduc wrote:

Like this?

home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

That is a substitue for the early Kaw igniter.

With a few more components, and some know-how, you can make the dwell extend more in order to use slower coils, or you can make the dwell shorter to use faster coils.

loudhvx wrote: I posted this years ago, but I guess it must not come up on searches.

1981 KZ550D1 (Gpz) ignition notes 8/14/05, updated 8/10:

Coils:
Primary DC resistance: Factory specs are 1.8 to 2.8 ohms. Actual measurements tend to be 2.4 to 2.7 ohms.
Primary inductance: 6.33 mH (Measured)

Lou,

I just purchased new Kawasaki ignition coils (part #21121-1035, 21121-1036) for my '81 Gpz550. I tested the new coils and the primary resistance was 3.4 OHMS for both coils. Is that too high to be concerned with? The secondary resistance tested 15,000 OHMS, which seems a bit high for new coils. I have not taken the old coils off yet to test them, but since they are 30 years old, I will replace them anyway, since I have an intermittent misfire on two cylinders. Thanks, Robert

GPz550D1 wrote:

loudhvx wrote: I posted this years ago, but I guess it must not come up on searches.

1981 KZ550D1 (Gpz) ignition notes 8/14/05, updated 8/10:

Coils:
Primary DC resistance: Factory specs are 1.8 to 2.8 ohms. Actual measurements tend to be 2.4 to 2.7 ohms.
Primary inductance: 6.33 mH (Measured)

Lou,

I just purchased new Kawasaki ignition coils (part #21121-1035, 21121-1036) for my '81 Gpz550. I tested the new coils and the primary resistance was 3.4 OHMS for both coils. Is that too high to be concerned with? The secondary resistance tested 15,000 OHMS, which seems a bit high for new coils. I have not taken the old coils off yet to test them, but since they are 30 years old, I will replace them anyway, since I have an intermittent misfire on two cylinders. Thanks, Robert

Strange. Do they have "TEC" logo on them? You have the correct part numbers, but I wonder if they actually gave you the correct coils. The higher ohm coils for the KZ550A1 look the same. I don't think I remember seeing a part number on the actual coils themselves. Did they come in a bag with the Kawasaki label and part number on them?

(Incidently, the KZ550A1, which has points, is listed with the 21121-1035 coil. This is an error, I believe. It would not share the same coil as the electronic models. The other coil on the KZ550A1 has a different part number altogether.)

The actual ohms is mainly a concern for the maximum current the igniter will see. Higher ohm coils are safer, from a heat and breakdown standpoint. However, higher ohm coils typically have higher inductance. This means the coils charge slower. That becomes a problem at higher RPMs where the coils have much less time to charge. Typically, the coils only reach about 1/2 of their normal charge state at 10,000 RPMs. With 3-ohm Accel or Dyna coils, the ignition gets close to failing to spark at 10,000 RPM and wide open throttle, but still seem to work fine, at least on the 81-83 gpz550's. (10.0:1 comp.)

With normal spark plug gaps, I would expect the 3.4 ohm coils may work fine as long as the engine has stock compression. It's usually when there are other motor changes that a weaker ignition starts to show problems. If it seems to stutter at higher RPMs with higher throttle openings, then it may be the coils are too slow.

If you are stuck with the coils, there may be an HEI igniter modification we could try to get them to work ok.

Lou,

Thanks for the response. The new coils came in the correct Kawasaki box and were wrapped in plastic bags. They both had the correct Kawasaki part number on two different labels attached to the boxes. The coils are slightly different in appearance to the original TEC (Tokyo Electric Co.) coils, but have the TEC logo in a different location, although the logo was very small and hard to find. It was behind one of the mounting bolts. They may be an updated design, although they look like a step backwards from the original coils. There are no part numbers stamped into the coils themselves. The new coils both have the positive and negative connectors attached to the coil in the normal location instead of the pigtail connectors that I believe the earlier KZ500/550's had. For some reason they were cheaper ($68 net, $90 list apiece) than other factory (TEC) coils for Kawasaki inline fours that I have seen. I will take the old coils off and test them to compare with the new ones. Sounds like the new coils will run slightly cooler, but have less voltage to the plugs. I am running a stock bike, but like to run it up to 9500 rpm on occasion. I am intalling new NGK LDO5F plug caps and D8EA plugs also. Thanks again for your thoughts!

Robert

Also, I know what you mean when you say the coils for the KZ550-A1 listed by Kawasaki seem to be wrong or at least one of those part numbers is wrong. The 21121-1011, which is discontinued and is for the #2/3 coil lists for $186.82, while the 21121-1035 for #1/4 lists for $90.18. I do not understand that one! I ran the part number 21121-1010 and it lists for $186.82, so that may actually be the correct part number for #1/4 coil on the KZ550-A1.

Robert

Oh yeah. I forgot the points coils had pigtails. Then I wonder just what those coils are that you got.

Good idea on the price check for the 21121-1010. I bet you're right about that being the correct A1 coil part number.