Vibration! A cure for bad vibrations, Spark Plug Caps!!

[trepetti]

Yes I was hesitant when I first thought of the idea of replacing the standard coils with COPs. Once I started finding some links and examples of other bikes being converted I thought I'd give it a go. Having the coils wired in series isn't ideal as if one coil open circuits the other one will too, so you lose 2 cylinders instead of just one, but that's how the bike was all along with 2 coils for 4 cylinders so there's no real change. Having them wired in series creates a bit more resistance than standard (I measured 2.4ohms with my coils in series compared to a standard original coil spec of 1.5-2ohms) so there is less current flowing through the transistors in the ECU, but a bit more resistance/less current flow is better than too much current IMO.
I played around with a neat android app called Circuit Jam and it's basically a geeky game based on electronic circuits. After you solve a heap of puzzles it unlocks components in a sandbox so I was able to create the circuit with coils wired in series and parallel. Here is the series wiring showing 2 COP coils with an average of 1.4ohms. Across each coil there's a 7.2volt drop, and 5.14 amps flowing though each coil, making around 37watts of power flowing through each coil.
View attachment 69431


Next up I played around with the idea of a parallel circuit, but to restrict the current flow though the transistors I would need a 1.3ohm resistor. This meant that now I only had 3.6 amps flowing through each coil, with 5 volts across the coils, which works out to around 18 watts at each coil.
View attachment 69432

I'm not sure how it's all going to last in the long run but so far the bike runs really nicely, in fact its been years since it ran this smoothly! The coils fit nicely but when they click down onto the spark plugs it feels like they have only grabbed onto the top thread, instead of the original caps where you could feel it clicking down on several threads on the top of the plug. I might have to look at trimming the rubber grommet to allow the coils to fit a little lower onto the spark plug but I'll worry about that if I see lots of arcing on the top of the plugs.

Anyway thank you again for everyone's help on this forum. Sorry for geeking out a bit in this post.

I am watching this closely. Definitely a mod I will do if it works out.

I like to see things simply....
- lower wattage of mod should mean cooler running transistors in the ECU
- series wiring presents no reliability loss compared to oem
- concerned about heat/duty cycle of COPs. Waste spark mode means 100% increase in duty cycle, can the COPs operate at that frequency and manage heat?. A shorted coil will fry the ECU

Also curious about the COP to plug connection. Perhaps additional resistance adding to heat load on the COP?

Anyway, I'm interested brother. Please keep us informed. My 05 with 55k miles will need coils someday, would rather do this in the off-season with newer FZ07 coils and be done with it.

Good luck brother!

 

[buzzbomb]

Re, the clicking on of the caps. Try putting a little dielectric grease on the rubber where it meets the valve cover. The rubber gets hard over time (many heat cycles). The grease makes slipping them on and off MUCH easier.

I don't have the COP but just the regular plug caps, this makes a BIG difference..

Gotta love the dielectric grease! I keep it handy for certain jobs. Definately helped installing the coils when I put them in. They take a bit of effort to get out so they won't shake themselves out any time soon.

 

[buzzbomb]

I am watching this closely. Definitely a mod I will do if it works out.

I like to see things simply....
- lower wattage of mod should mean cooler running transistors in the ECU
- series wiring presents no reliability loss compared to oem
- concerned about heat/duty cycle of COPs. Waste spark mode means 100% increase in duty cycle, can the COPs operate at that frequency and manage heat?. A shorted coil will fry the ECU

Also curious about the COP to plug connection. Perhaps additional resistance adding to heat load on the COP?

Anyway, I'm interested brother. Please keep us informed. My 05 with 55k miles will need coils someday, would rather do this in the off-season with newer FZ07 coils and be done with it.

Good luck brother!

Hey Trepetti thanks for the reply!

I was curious to know about the heat and duty cycle at full revs when I was installing the COPs, and the longevity is still an unknown factor. There seems to be enough spark energy despite only having half the voltage running across the coils, and restricted dwell time to charge the coils, but it ran cleanly up through the rev range on my test ride.

As for the resistance of the plug connections, I checked the resistances as I was working out wire placement, and found no issues with the clip. They lock on securely with a positive click and good connections. I decided to run the wiring along the back of the cylinder head rather than the front and bought some nylon sheathing and heatshrink to make the wiring look neat and professional.

I will keep you guys updated over the next few months. Now that it's registered and the weather is warming up (in this part of the world at least!) I want to get back into riding again.

Thanks again!

BB

 

[buzzbomb]

Another option would be to add your own external switches. Like four fast switching FETs with a heat sink each rated at 60w or so. Keeping in mind the ECU is pulling these to ground. This would unload the ECM from doing any work. The problem now is that the ECM doesn't see the expected impedance and throws an error.

Something to think about.

Interesting option you raise there FI, I had thought of doing something along the lines of MOSFETs but haven't really played around with them before. That would solve the power issue and separate it from the ECM completely, allowing you to run the coils at full power. I would think that would give the coils a faster charge up time, but may run the coils hotter as they're firing twice as often.

For the time being I can put down the spanners and enjoy the bike with everything back together...you guys don't know how long my poor bike sat with the fairings off and the tank up! I was pulling out my hair trying to pin down the vibes. It was just a shame that I didn't notice earlier that the old coils were out of spec in regard to primary resistance. I tried changing the leads but that created it's own headaches, when I should have changed coils sooner.

Cheers,
BB

 

[FinalImpact]

Interesting option you raise there FI, I had thought of doing something along the lines of MOSFETs but haven't really played around with them before. That would solve the power issue and separate it from the ECM completely, allowing you to run the coils at full power. I would think that would give the coils a faster charge up time, but may run the coils hotter as they're firing twice as often.

For the time being I can put down the spanners and enjoy the bike with everything back together...you guys don't know how long my poor bike sat with the fairings off and the tank up! I was pulling out my hair trying to pin down the vibes. It was just a shame that I didn't notice earlier that the old coils were out of spec in regard to primary resistance. I tried changing the leads but that created it's own headaches, when I should have changed coils sooner.

Cheers,
BB

OK so bottom line is this. Another situation where cutting, trimming, coil replacement doesn't fix this bike but let us not loose focus on the root cause.

The ignition system induced a horrid vibration!!!!!!!!!!!!
This is NOT NORMAL!
I got lucky as I saw it change every time I touched it!
Others did not, but still, this engine can be very smooth when all things are proper!!!!

Don't give up people! Don't give up!

I am glad you went to an extreme and it worked! Good job!

I ride way to deep into no-man's land so reliability is everything to me. I'm not willing to risk walking 100mi in my boots just yet.
Let me noodle on this...

Be safe!

 

[FinalImpact]

Yes I was hesitant when I first thought of the idea of replacing the standard coils with COPs. Once I started finding some links and examples of other bikes being converted I thought I'd give it a go. Having the coils wired in series isn't ideal as if one coil open circuits the other one will too, so you lose 2 cylinders instead of just one, but that's how the bike was all along with 2 coils for 4 cylinders so there's no real change. Having them wired in series creates a bit more resistance than standard (I measured 2.4ohms with my coils in series compared to a standard original coil spec of 1.5-2ohms) so there is less current flowing through the transistors in the ECU, but a bit more resistance/less current flow is better than too much current IMO.
I played around with a neat android app called Circuit Jam and it's basically a geeky game based on electronic circuits. After you solve a heap of puzzles it unlocks components in a sandbox so I was able to create the circuit with coils wired in series and parallel. Here is the series wiring showing 2 COP coils with an average of 1.4ohms. Across each coil there's a 7.2volt drop, and 5.14 amps flowing though each coil, making around 37watts of power flowing through each coil.
View attachment 69431


Next up I played around with the idea of a parallel circuit, but to restrict the current flow though the transistors I would need a 1.3ohm resistor. This meant that now I only had 3.6 amps flowing through each coil, with 5 volts across the coils, which works out to around 18 watts at each coil.
View attachment 69432

I'm not sure how it's all going to last in the long run but so far the bike runs really nicely, in fact its been years since it ran this smoothly! The coils fit nicely but when they click down onto the spark plugs it feels like they have only grabbed onto the top thread, instead of the original caps where you could feel it clicking down on several threads on the top of the plug. I might have to look at trimming the rubber grommet to allow the coils to fit a little lower onto the spark plug but I'll worry about that if I see lots of arcing on the top of the plugs.

Anyway thank you again for everyone's help on this forum. Sorry for geeking out a bit in this post.

Any updates on this?
Also, although the stock system is waste spark it is in fact firing for each compression stroke. That said both oem and your COP setup are being fired at the same rate for any given RPM so the concern about dwell time is not really a factor in terms of rate of discharge given the same RPM.

Series coil energy
Speculation is this: cylinder pressure impacts spark energy just like a lean or rich fuel ratio does.

We are not talking extremes here but rich AFR takes less spark energy to jump the plugs gap than lean AFR.
That said, no cylinder pressure **likely means** the spark energy needed to jump the plugs gap on the cylinder not being fired is much lower thus your series connection works as the coil energy is driven by demand rather than being split equally regardless of what is happening in the combustion chamber.

If you were to place test leads of an oscilloscope across both input coils and measure the voltage you would see that the cylinder being fired loads the coil drawing more current. That said I believe the series wiring of the coils works based on cylinder combustion pressure literally driving the current demand for spark energy based on which cylinder is being fired.

I see those who think in terms of a current (amps) through the primary coils when wired in series concluding it must be equal therefore any spark delivered by the secondary winding should be equal. Believe me, in my mind I think this too. But without measuring this with an oscilloscope I can't prove it. But I do know cylinder loading drives the demand just like the waste spark system does.

Let us know how this working for you!

 

[Motogiro]

If we see a drop in that secondary voltage, should we not address this variable in relation to the spark plug gap? Again we need an O'scope to really see what the truer story is. Maybe the sweet spot would be 24-28 VDC at the coil primary input if you're running the COP's in series? But again what are the ECU switching transistors seeing voltage wise? We've got 2 primary windings that are nice fat inductors and when we cut them loose is there a big spike or interference with the field collapse? So Q or impedance may be a larger factor that needs attention as we're not just dealing with DC. As rpm or frequency changes the impedance will change.

 

[trepetti]

I can't take it anymore! I ordered 4 FZ07 coils. I am taking the plunge!

It all started this weekend when I did a TB sync and the bike runs smooth as silk. I am a believer [MENTION=15974]FinalImpact[/MENTION], there is no reason to put up with lots of vibes. I trimmed the plug wires over the off season and things got a little better, then WHAM the TB sync tied it all together. Now I am going to try the COP mod.

It never ran this smooth!

FYI I highly recommend the CarbTune. I had a home made manometer that didn't age well so I bought the CarbTune directly from their website in the UK. Price qas under 100 with shipping and arrived in a week. Very nice tool.

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[FinalImpact]

I can't take it anymore! I ordered 4 FZ07 coils. I am taking the plunge!

It all started this weekend when I did a TB sync and the bike runs smooth as silk. I am a believer [MENTION=15974]FinalImpact[/MENTION], there is no reason to put up with lots of vibes. I trimmed the plug wires over the off season and things got a little better, then WHAM the TB sync tied it all together. Now I am going to try the COP mod.

It never ran this smooth!

FYI I highly recommend the CarbTune. I had a home made manometer that didn't age well so I bought the CarbTune directly from their website in the UK. Price qas under 100 with shipping and arrived in a week. Very nice tool.

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Question; are you saying you've cut the wires twice and seen improvement each time??
And now you have also ordered COPs?

I will say it can be a night and day difference. And very few S1 failures compared to S2....

 

[FinalImpact]

Also I think the trifecta is valve adjust, wires fixed, TB sync. Super smooth!!!

Keep us posted!

 

[trepetti]

Question; are you saying you've cut the wires twice and seen improvement each time??
And now you have also ordered COPs?

I will say it can be a night and day difference. And very few S1 failures compared to S2....

I cut the wires once this last winter. Did a valve adjust in December 2017 but never did thebtb sync till this last weekend. So it was the trifecta spread out over 17 months [emoji3].

And yes, doind the COP soon. I have 2 coils here, 2 on the way and just ordered the connectors from cycleterminal.

Will send updates as things develop.

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[trepetti]

Making progress. 'Lead' coils (cyl 1 and 2) wired up, grounds for 2 and 4 done. Need to measure, trim and crimp series connections. Then bring my 2 hot and 2 ground wires up and connect to bikes harness. [MENTION=2691]buzzbomb[/MENTION], still working well? Any tips on sleeving the new wires?

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[FinalImpact]

Go big or go home! Haha!
In the electrical is a sticky for where you bought your parts. Look through there for adhesive lined heat shrink tubing. The stuff is the bomb! Just don't make any mistakes!

Maybe carry a spare ECM when deep in the woods! Blah

 

[FinalImpact]

You know if you put the R6 cams and valve cover you get a camshaft position sensor and then you can add some trickery to only fire the coil needed for combustion!

Sure he says....

 

[buzzbomb]

Hi Trepetti, good luck with your COP installation! A few tips from my installation:-
- Slide the rubber seal on the COP up a few millimetres, so it's touching the electrical connector. This lets you push the coil down a little bit further so it clicks onto the spark plug nicely and won't come loose.
- Give yourself more wire than you think, so you can lay the wiring on the back edge of the rocker cover, just in front of the throttle intakes. Also I covered my wiring with nylon braid and heat shrank the joins to make it look neat. I noticed you also have some in the photo. The ends can fray so a lighter is good to just melt the ends so it stops fraying.
- Take lots of photos before you start, and write down a sketch of the orange/grey wires and their corresponding coils.
-Wiring in series is the only practical way of wiring. It results in a slightly higher resistance than factory coils. If it's wired in parallel it virtually halves the resistance seen by the ECU and that's Bad.
- Check the resistance of your COPs. They should be around 1.19 to 1.61Ohms. Most of the modern Yamaha COPs are around this level. Only ones I heard of that were different were some early R6s from memory. I bought 2 from a Yamaha MT07 and a couple from a Yamaha FJR1300, and they were all virtually the same resistance.
Hope this helps. Good luck and let us know how you go! I haven't been riding my bike much lately due to family commitments but still runs nicely.
BB

 

[trepetti]

Hi Trepetti, good luck with your COP installation! A few tips from my installation:-
- Slide the rubber seal on the COP up a few millimetres, so it's touching the electrical connector. This lets you push the coil down a little bit further so it clicks onto the spark plug nicely and won't come loose.
- Give yourself more wire than you think, so you can lay the wiring on the back edge of the rocker cover, just in front of the throttle intakes. Also I covered my wiring with nylon braid and heat shrank the joins to make it look neat. I noticed you also have some in the photo. The ends can fray so a lighter is good to just melt the ends so it stops fraying.
- Take lots of photos before you start, and write down a sketch of the orange/grey wires and their corresponding coils.
-Wiring in series is the only practical way of wiring. It results in a slightly higher resistance than factory coils. If it's wired in parallel it virtually halves the resistance seen by the ECU and that's Bad.
- Check the resistance of your COPs. They should be around 1.19 to 1.61Ohms. Most of the modern Yamaha COPs are around this level. Only ones I heard of that were different were some early R6s from memory. I bought 2 from a Yamaha MT07 and a couple from a Yamaha FJR1300, and they were all virtually the same resistance.
Hope this helps. Good luck and let us know how you go! I haven't been riding my bike much lately due to family commitments but still runs nicely.
BB

Thinking that today is the install day. Once I get the spacing measurement I can finish terminating the harness and wrap it up. I have worked with the braided loom before, and I consider it more decorative than functional. Now that I have decided to copy your idea of running the wiring in the back, I am pretty sure that I am going to use plain-old 3M 33+ electrical tape. Meets the environmental specs and easier to work with.

3 of my 4 coils came in at 1.3 ohms, the fourth at 1.4, so things are good. I used 2 different color schemes, Red/Black for 1-4 and Blue/Green 2-3, so wiring won't be a problem. I might replace the connectors on the bike's harness with 2 new waterproof connectors. I usually take 2 different styles s that they cannot be connected wrong, but that is later.

Thanks for the tips..... Look for pictures soon.....

 

[trepetti]

Harness done. Need to find time this week to pull the airbox and install.

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[trepetti]

DONE! Made the swap yesterday, went for a 50 mile check ride this morning took a 240 mile ride. Subjectively much less vibration, seems to pull better at lower revs. Objectively, fuel mileage is up.

Will continue to report back, first impressions are that there have been improvements in drive-ability.

 

[trepetti]

Thanks [MENTION=2691]buzzbomb[/MENTION] for the great write up on your COP mod. Between that and the help of Joe Sciavone at Cycleterminals.com the install was a piece of cake. Considering the lousy connections on both sides of the high-tension leads on the stock coils, this seems a worthwhile mod.

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[buzzbomb]

Awesome trepetti! Glad to hear your happy with the COP mod!