Coil Mod - should I do it?

[Speedo]

5. Lastly - perhaps unrelated but maybe and certainly significant: Volts at Coil Test (from Wired George link off BassCliff's site):

1-4 coil: 9.7v (should be 12)
2-3 coil: 9.8v (sb 12)

So looks like, in addition to the connectors cleaning "project", the coil relay rewiring is in line as well. More reading/homework for me!

Things sound like they're working out for you now. When you get to the front and get inside the headlight bucket if you remove the 2 bolts holding it to the mounts you can move it out of the way and easily remove the ignition switch and clean the contacts on it. Not that there's anything wrong with doing the relay mod but that'll probably fix your problem with the voltage to the coils.

just to clarify, those mods may be good for getting better voltage at the coils and the headlight but as far as the charging problems go they won't help any

To Psyguys's point, entirely different subject as far as coil mod, so I am starting a different post on this.

I'm looking for experience-based input/advice. I read all the stuff on BassCliff's site (what a great site!) and here are my qq so far:

1. Should I do this? Is it "worth" it? Bike has not been running bad, no sooty plugs, major carb problems, etc. Will it make a difference?

2. Looks like several different variations/approaches. Any pros/cons?

3. As far as relay - use 4 wire, 5 wire, should I care? What about a 5 prong "87a" relay (only relay first place i went to had) - can I use it?

4. Wiring: using stock wires no longer used after stator direct rewire (one method on BassCliff site) makes me nervous. 30yr old wiring harness, I'm thinking to bypass whenever practical/possible. Opinions?

5. Anyone get results from cleaning ignition switch per Sandy above - as far as volts to coils (obv cleaning contacts can't hurt)?

6. Relay location: near coils or back by battery? Near coils makes sense but makes me nervous as there way more heat up there i'm thinking...

[BassCliff]

Hi,

With that kind of voltage drop, you should notice a difference after a coil relay mod, like instant starts. I put my relay next to the battery box near the fusebox under the left sidecover.



Thank you for your indulgence,

BassCliff

[fenderfreek]

To Psyguys's point, entirely different subject as far as coil mod, so I am starting a different post on this.

I'm looking for experience-based input/advice. I read all the stuff on BassCliff's site (what a great site!) and here are my qq so far:

1. Should I do this? Is it "worth" it? Bike has not been running bad, no sooty plugs, major carb problems, etc. Will it make a difference?

2. Looks like several different variations/approaches. Any pros/cons?

3. As far as relay - use 4 wire, 5 wire, should I care? What about a 5 prong "87a" relay (only relay first place i went to had) - can I use it?

4. Wiring: using stock wires no longer used after stator direct rewire (one method on BassCliff site) makes me nervous. 30yr old wiring harness, I'm thinking to bypass whenever practical/possible. Opinions?

5. Anyone get results from cleaning ignition switch per Sandy above - as far as volts to coils (obv cleaning contacts can't hurt)?

6. Relay location: near coils or back by battery? Near coils makes sense but makes me nervous as there way more heat up there i'm thinking...

1. Yes. Even if you're not having trouble now, history shows that you likely will. Go ahead and give yourself one less thing to worry about later. It's simply a better design, and it sure won't hurt.

2. There's not much variation to it - the orange/white connects to the relay trigger, and the other side of that to ground. The hot from the battery goes through a fuse to the NO terminal of the relay, and the other side of that circuit goes to the coils. You want that kill switch wire to actuate the relay, rather than directly feed the coils.

4. I used all new wire. I cut the O/W wires at the coil and spliced them into a length of 12g that went to the relay for the control. I used a single 10g back toward the coils, and made a little "T" splice. Each leg of that "T" has a spade connector and goes to a coil.

5. I didn't bother. Tearing into that would have taken as long as this did, and this is an actual fix for the problem, not a bandaid fix.

6. I put mine back beside the battery. There's a medium-gauge wire running from the cut/spliced orange/white's back to the relay, and one heavy wire going from the relay back up to feed the coils. As long as you use the correct gauge of wire and good connections in your circuit, the few inches of difference will not introduce any voltage loss. Putting that relay up by the coils, however, may well introduce some serious heat issues.

[KiwiGS]

To Psyguys's point, entirely different subject as far as coil mod, so I am starting a different post on this.

I'm looking for experience-based input/advice. I read all the stuff on BassCliff's site (what a great site!) and here are my qq so far:

1. Should I do this? Is it "worth" it? Bike has not been running bad, no sooty plugs, major carb problems, etc. Will it make a difference?

2. Looks like several different variations/approaches. Any pros/cons?

3. As far as relay - use 4 wire, 5 wire, should I care? What about a 5 prong "87a" relay (only relay first place i went to had) - can I use it?

4. Wiring: using stock wires no longer used after stator direct rewire (one method on BassCliff site) makes me nervous. 30yr old wiring harness, I'm thinking to bypass whenever practical/possible. Opinions?

5. Anyone get results from cleaning ignition switch per Sandy above - as far as volts to coils (obv cleaning contacts can't hurt)?

6. Relay location: near coils or back by battery? Near coils makes sense but makes me nervous as there way more heat up there i'm thinking...

1. Yes it is worth it, my bike was a pig to start. Did the mod now it starts easy.
2. Not sure, simple is good.
3. I used the "87a" just 'cause that is what I had.
4. I got rid of the stock connectors where I could, I went to green dynas at the same time so I had to.
5. I cleaned the contacts at the same time, I guess it could make the relay work a bit more crisply
6. Before I moved the 'lectrics under the seat I had the relay cable tied to the frame near the coils, I had no issues.

Cheers

[woodman]

All of my KZs & Z1s are done but the GS had good voltage at the coils so I didnt do it. I put everything by the battery so it can be changed back if theres a problem. Green Dynas are a huge improvement

[Speedo]

Woodman - mine has green dynas (coils that is). What were your readings?

[lucabond]

I think I disagree with psyguy as to the mod helping your charging system. If your old harness with all the connectors and old wire that may be water infiltrated is acting like a big resistor it will drop the voltage available to charge the battery. The more voltage at the coils means the spark should be better while at the same time taking load off the harness leaving voltage for the rest of the bike. The headlight draws a lot of current leaving less for the coils and the rest of the bike. These bikes only produce about 15 amps if a portion of that is lost in the harness due to poor wiring it's being wasted. I know on my bike I found wires that have a black coating on the strands inside which is caused by water getting in decreasing their ability to carry current which drops as it is eaten up by the poor wire itself let alone the connectors. Just my 2 cents.
The 87a work gust fine , I believe that's the 1 in the coil mod write up. Just use the wire that powered the coils as your switched wire. I have mine mounted in back by the battery. For the headlight I just ran a wire to the handle bar switch. Just cut the wire that feeds the light at the plug and connect the new wire to it that way the low and high beam both work. You can use the same switched wire for both coils. Good luck

[chef1366]

Takes 20 minutes and helps cold starting.
Can't hurt can it?
Carry a spare relay.

[Steve]

To Psyguys's point, entirely different subject as far as coil mod, so I am starting a different post on this.

I'm looking for experience-based input/advice. I read all the stuff on BassCliff's site (what a great site!) and here are my qq so far:

1. Should I do this? Is it "worth" it? Bike has not been running bad, no sooty plugs, major carb problems, etc. Will it make a difference?

2. Looks like several different variations/approaches. Any pros/cons?

3. As far as relay - use 4 wire, 5 wire, should I care? What about a 5 prong "87a" relay (only relay first place i went to had) - can I use it?

4. Wiring: using stock wires no longer used after stator direct rewire (one method on BassCliff site) makes me nervous. 30yr old wiring harness, I'm thinking to bypass whenever practical/possible. Opinions?

5. Anyone get results from cleaning ignition switch per Sandy above - as far as volts to coils (obv cleaning contacts can't hurt)?

6. Relay location: near coils or back by battery? Near coils makes sense but makes me nervous as there way more heat up there i'm thinking...

1. You are quoting others, why not quote Nessism, too? "To measure is to know." If those numbers are your readings, something needs to be done, but only after knowing the conditions under which those readings were taken. Was the ignitin switch ON, but the engine OFF? Was the engine running over 3,000 rpm? The voltage at the coils should be measured with the engine running.

2. I have not noticed any variations other than relay location.

3. You can use an '87a' relay, just don't use terminal 87a. Connect #85 or 86 to the coil wire, the other one to ground. Run your power from the battery to #30, then #87 to the coils.

4. One of the reasons to do this mod is to eliminate bad connections. The only way to eliminate them is to bypass them. Some have then used the bypassed wires for other stuff, but not the high-current loads of the coils.

5. Have not had to clean an ignition switch (yet), but that could help by increasing voltage/current to ALL circuits on the bike, not just the coils.

6. There are three relays on my wife's bike. Two are inside the left side cover, the third is up near the coils. No problems out of any of them.

Just for general information: my wife's bike has started and run well ever since the carbs were cleaned and the valves were adjusted. I have never even measured the voltage at the coils. I have not done the coil mod because we have not had problems. The three relays on her bike are for 1) headlight cut-out, 2) power to accessory terminal strip and 3) horns.

I think I disagree with psyguy as to the mod helping your charging system. If your old harness with all the connectors and old wire that may be water infiltrated is acting like a big resistor it will drop the voltage available to charge the battery.

Doing just the coil relay mod or the headlight mod (or both) won't have anything at all to do with charging. In other words, if your voltage at the coils is only 9 volts, you do the coil mod and it goes to 13 volts, your voltage at the battery will remain the same. Don't do this mod to improve your charging capability. The coils are simple devices, they do not compensate for their output. If they only see 9 volts coming in, they simply put out less to the spark plugs. If, however, they were to monitor the output and try to keep it constant, drawing more power to do so, yeah, that could affect the load on the battery, but that is not the case. As long as your connections between the stator, regulator and battery are good, your charging will be good.

[duaneage]

I cleaned the ignition switch and restored all the voltage to my coils. Did the run switch too. That's also an option for a hard to start bike.

[koolaid_kid]

General Information on Relays

A slight technical aside about relays in general:
Terminal number - function
85 - Relay Ground
86 - Relay Trigger (such as key on. Low current requirement, so you can use a 5-10A fused wire).
30/51 - High current power. Normally goes right to the battery.
87 - High current output when 86 is being supplied power. Also known as active on.
87a - High current output when 86 is not being supplied power. Also known as active off.
30/51 needs to be fused. Many wiring diagrams fuse the output (87/87a) rather than the input. This ignores the fact that the relay always has power to it. So, a short somewhere in the supply line to 30/51 will melt the wiring, lending to the possibility of fire, etc. Be double safe and fuse the input, near the battery, not the output.

A relay is used to supply clean, 12v high current power to a device, such as a set of horns, coils, or any other device that requires it, using a low current source, such as a key on power wire. It is a sink of power (uses it) not a source (creates it).
Hope this helps.
p.s. Please note, this is directly applicable to the Bosch style relay, which is the de facto standard for automobiles.

[Steve]

A slight technical aside about relays in general: ...

Basically, what he's saying is that it's just a remotely-controlled switch.

Too many times people think that a relay is a piece of magic that does wonderful stuff. Well, it can, but it's not. It's just a switch.

.

[koolaid_kid]

That is correct, Steve. But it allows you to send a lot of current w/o burning out the switch on the bike (key on, horn button, etc.). So, you could think of it as a high current switch controlled by a low current switch.

[lucabond]

It works the same as the starting solenoid which is a relay. Just as the last post said it allows a high current to be switched by a low current.

[Steve]

Basically, what he's saying is that it's just a remotely-controlled switch.

That is correct, Steve. But it allows you to send a lot of current w/o burning out the switch on the bike (key on, horn button, etc.). So, you could think of it as a high current switch controlled by a low current switch.

It works the same as the starting solenoid which is a relay. Just as the last post said it allows a high current to be switched by a low current.

All of this is just different ways of saying the same thing.

.