Rebuild: Do i replace my coil etc?

loudhvx wrote: I can't see the photos from work, but some of the 750's, at least in Europe, had a resistor for the headlight to make it a tad dimmer. It looked like a green cylinder.

You can get a very close replacement for the coil from Z1 enterprises, made by Emgo. Some have reported it works well.

That sounds exactly what it is by your description, after all this is a euro bike, Z750. I'm replacing the headlight so will i need to keep it?

Is the coil you're talking about an original equipment replacement? Would i not be safer adding a dyna coil if im replacing? I see nothing wrong with the coil i have, just when im doing this project a new coil is a minor outlay when im doing it, especially with your kind help in the rewire diagram


The white item, i believe to be the coil, has on it 'Nippon Denso", "12v" & either "3(zero) or 3O (O being the letter)), i assume this is 3ohms?, i find it strange they wouldnt use the ohm symbol though, like my keyboard doesnt have!

You can just eliminate the headlight resistor.

I thought the original brand name on all KZ coils was "TEC". If it's Denso, someone may have put in an aftermarket coil, or coil from another brand... (sort of like the Honda regulator you found on the bike).

Some of the old coils were sort of pinkish, and could fade out to an off-white color. I'm pretty sure the originals were 4-ohm coils on the points bikes. 3-ohm will work, but may shorten the life of the points. I think Dyna has a 5-ohm coil that some people are using on the Twins forum. They say it works fine. The original was 4-ohms. The Emgo is 4-ohms, and is very cost effective, but I can't say how reliable they are... I've never seen one in person.

A thirty-plus year old coil may get you stranded after some rain, so it's one part I think is worth updating after 15 to 20 years or so.

One way to be sure if the resistor coil with the Two blue wires is for the Headlight or coil, is what does it plug into? What are the wire colors that i t plugs into, Blue still? I know you're stripping it down now, but if you can use your OHM meter to check where the circuit goes, to the Ignition coil or to the head light.
The EMGO replacement coil for your Twin should be fine, like Loudhvx, I'm sure the Points coil would be 5Ohm with the points set-up.

loudhvx wrote: The Emgo is 4-ohms, and is very cost effective, but I can't say how reliable they are... I've never seen one in person.

Is the Emgo 4-ohm better for me then?, i mean by that is 4-ohm going to create a better/fatter spark than a Dyna Coil 5-ohm with it having less resistance? The Dyna Coil is $70ish & to be honest i dont mind putting that money into it. I just read all that Dyna Coil 'this & that' but i do wonder why they are so good (supposedly), what are their advantages over a STD coil?

Motor Head wrote: One way to be sure if the resistor coil with the Two blue wires is for the Headlight or coil, is what does it plug into? What are the wire colors that i t plugs into, Blue still? I know you're stripping it down now, but if you can use your OHM meter to check where the circuit goes, to the Ignition coil or to the head light.
The EMGO replacement coil for your Twin should be fine, like Loudhvx, I'm sure the Points coil would be 5Ohm with the points set-up.

It does plug into a blue wire again & i traced that blue wire to the switchgear if i remember correctly. How do i measure the resistance across the coil? Do i use 1 plug cap or does it need to be both?

*edit* i just checked the 60 or so pics i took when stripping the bike & it actually looks like it went to the coil.

MFolks wrote: It's wire wound resistor(the green tubular item)but I'm not sure what the white item is. Any voltages or amps marked on it?

Sorry, i missed this. There are no markings on it whatsoever

I've just seen this on the Z1 site about the green 3-ohm coil, with particular interest to the last sentence.

Dyna Dual Output 3.0 Ohm Coils (single) DC1-1
DYDC1-1-single

OEM: DYDC1-1-

(used with twin cylinder bikes fitted with one dual output coil) 3 ohm green coils. Replacement for factory coil. Matched to the Dyna-S Electronic Ignitions. Fatter spark means smoother running and less chance of fouling a plug. See below for plug wires.
Check the resistance of the coils you are replacing to ensure a correct match. These coils work to replace some point system coils where the resistance is in the low to mid 3 ohm range. For some Kawasaki bikes with a 1.5ohm ballast resistor in the circuit, the 3 ohm coil is the best choice - just remove the ballast resistor from the circuit.

Dyna Coil is £53 shipped from USA (they seem to be like £90 in the UK!!!!), pattern coil is £40 shipped from UK (dont see the pattern part on Z1's site), or £28 on ebay.

When im buying leads too do i go for suppression core or copper core?? & what type of plug caps? No resistor or resistor, & if resistor ones then what resistance?

The green thing seems to have a resistance of 1-ohm. Still trying to figure how to measure the coil's resistance!

Measure the OHMs across the two Primary connections, that is where the power and Points wire connects. As for the secondary side, if you're going to replace it then it shouldn't matter. It is the Primary side that is what you are matching up for your systems set-up. Coils have a Ratio of 100:1 or 150:1 usually. That's 100-150 windings of wire in the High secondary side, compared to the Low primary side.
The 1 Ohm Green resistor coil, going to the Coil, is a Ballast resistor. That effectively lowers your voltage across the Points contacts, so they don't arc as much making them last longer. If you stay with a points Ignition, then I would keep the resistor. Setting up the points correctly, making sure of the mechanical advancer function, and having a new coil with new wires should make all kinds of spark.
I'm a firm believer in replacing both the points and condenser, at the same time.
You could also take a couple of other directions with the Ignition, and get rid of the points. Then you may want a different coil, and get rid of the resistor.

Motor Head wrote: If you stay with a points Ignition, then I would keep the resistor. Setting up the points correctly, making sure of the mechanical advancer function, and having a new coil with new wires should make all kinds of spark.I'm a firm believer in replacing both the points and condenser, at the same time.

I'll be getting someone who knows what they're at to sort that bit out, he's doing the valve clearances as well & i might just sit in & watch him do it.

Motor Head wrote: You could also take a couple of other directions with the Ignition, and get rid of the points. Then you may want a different coil, and get rid of the resistor.

Now this sounds interesting, what do you suggest?, or rather what do you know? (WWW links to products etc)

Well the biggest Issue with points is the wear/ maintenance. So going over to an electronic ignition will get rid of those two things, and provide a better/ spark at all RPM. granted a Twin won't be spinning up much.
So then there is also the MSD boxes that still use the points for triggering, but are wired to route the power away from the contacts of the point set, so again you get rid of the resistor. Also a different coil.
so I believe you could mount up the Kawasaki Twin ignition from a later model. This has been covered in the past and there would be threads here and on the Armbell twin forum on converting. That would be the best route, in my opinion anyway. The OEM Kawasaki stuff is very durable.

I'm almost positive the resistor is for the headlight. You can see it on this 76 B1 diagram, and many posts on the twin sight from Europeans, say that resistor is for the lights, and specifically not for the ignition. That resistor does not appear to be a ballast type, which is what you'd use on an ignition. Ballasts are designed to increase resistance as they heat up, and they are usually a white rectangular ceramic on Kaws. Normal resistors don't change resistance appreciably with heat, and they are usually the tubular green ceramic, as they are just common resistors of that era.

At any rate, with a stock dwell near 180 degrees, you can use just about any modern coil from 3 ohms to 5 ohms with no resistor of any kind. I'm pretty sure the stock one was spec'd at 4-ohms. The Emgo one is 4-ohms, so that is closest. I think your Dyna options are 3 or 5 ohms. People on the twins sight use the 5 ohm coils or the 4-ohm Emgos. I haven't tried them, but search for posts by Bountyhunter and there are a couple other users on the twins sight using the Emgo. I believe Emgo made that coil specifically for Kawasaki bikes, as they made the coil look like the original ones on the inline-fours.