81 KZ750H LTD No spark

Well I looked through the list from the link provided and it appears the duralast dr100 is a 1.25V 4pin. It is also listed in the same category as the Wells model so I think they will work. I will bench test the old components before I install the new one and update with my results. Just to clarify, I will have to pull the battery to mount the aluminum backing plate for the new igniter unit correct? That’s what the site makes it look like anyway

The problem is that the modules are subject to change without warning.  Last I checked, the DR100 were still ok to use, but that can change anytime.  For example, the BWD CBE4P originally was the same as a DR100.  But BWD (formerly called Borg-Warner) suddenly changed to the newer, non-compatible type, so the BWD CBE4P is not recommended anymore.  It's been awhile since I created that list, so I can't say for sure if the DR100 is still made the same way, so I recommend checking with the battery and meter as shown in the link.

The aluminum plate shown on that page is over-sized because I was too lazy to cut it down.  It just simply bolts in place of where the original igniter mounted on a Kz550.  It can be installed and removed with the battery in place on a 550.  I'm not sure how/where the igniter mounts on a 750.

 

It appears to be in the same place, on the inside of the frame with the front facing the battery. Perhaps it would be better to leave it as large as possible to function as a better heat sink. It will all be covered anyway. Do I really need the resistors or can I test the bike for spark without them? Just impatient because I don’t want to wait for the resistors to come In. I decided against the duralast as they were $30 a piece and found genuine wells on rock auto for $12 a piece. Plus the NKG plug boots for $2 a pop when Amazon had them for nearly $6. 

It should be one resistor and two diodes.  Without those extra parts, the signal may be too weak to create spark during startup.  If the engine was somehow able to spin fast enough, the signal would be strong enough to create spark, but normal start RPM is usually too low to create spark without those parts.

If you get a bench setup for the original igniter, you can swap in the HEI modules and do a bench test on the HEI setup without the resistor and diodes.  You would use a manual switch to create spark.  I think I have a diagram for that somewhere. I'll try to post it when I find it.

I think Lou should gather up all his lovely diagrams and helpful instructions and make a book. It could be titled, The Book of Loutricity: Six Thousand Steps to Keep Your Old Japanese Motorcycle Sparking.

I would seriously buy this book, if you could drop that diagram I would love to have it. Hopefully rock auto delivers my parts before the weekend so maybe I can have some time on it this weekend. 

D'oh. The diagram I was looking for is already on the page I linked to.  You can test the igniters and coils with this setup:

Previous link:
gpzweb.s3-website-us-east-1.amazonaws.co...ion/GPZgmHEImod.html

Obviously you don't have to use actual switches.  You can just touch the red wire to the G terminal briefly.

 

What gauge wire does the whole new inverter need to be? I’ve got 18 and 14awg so I’m just curious and possibly overthinking it at this point. 

Between 14 and 18, I'd probably choose 18 for wires going to a single coil and 14 for wires that handle power for both circuits, like the main wire feeding the coils and the ground for the igniter(s).  If I had 16, I'd use that instead of 14.  The Kawasaki ignition is very efficient so it uses little average current, same for the HEI in this application.  Some automotive 14 is nice to use and some is a bit stiffer, more like stranded home wiring which is a pain to use.

The positive wires powering the igniter(s) use almost no power so they can be 18 for sure. 
The individual current paths from the coils to igniters can be 18 gauge.
The main current path for when the current for the two circuits is combined, is from the battery to the coils, and from the igniters to ground. Those should be 16 or larger. 
The control wires feeding the igniter(s) and pickups can be really small, but you probably want 18 just to have physically strong wires.

No eBay APP ID and/or Cert ID defined in Kunena configurationI’ve had good success with this. You can contact the seller and ask to swap the solid for two color. It really helps when adding relays and such to keep the factory color codes. 

Also here for terminals  vintageconnections.com/

Okay, I am going to do my assembly of the igniter tonight, I follow everyone’s input about the wires for the bench test, what about the actual igniter that will be on the bike? I plan to chop the connectors off the nonworking factory igniter and solder those to the harness for the new igniter, mount the control modules to 1/8” steel plate, and run the outgoing(coil) wires through that plug so I am not cutting the factory harness. Does anyone see a problem with what I have described here? Won’t be able to start until I get off work but this is my theory on how I can assemble it and make it as clean and OEM as possible. After that is done, it will be too late to put it on the bike and possibly start it up so I will probably ground the plugs to the block to test for spark and just have to fire it up in the morning. That is if all goes well. 

The wire gauges I mention were for the bike and bench test.

You can also just copy the wire gauges on the bike, or at least get close to it.  The wires on the bike are some Japanese standard or metric gauges, but you can eyeball it be close to AWG.

Did you setup a bench test with the original igniter?  I recommend doing that before cutting the wires off of the original igniter.