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4th gen Coil on Plug mod (split thread)


SEBSPEED

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Maybe you mentioned it before douglas, but what coils are you using? Also, out of curiosity do you have a voltmeter on your bike? If so, would you be able to let us know what your readings are at idle before and after the mod? I'm still confused why certain aspects of this mod didn't work so well for me. And let us know how it goes!


A good ride on the weekend....

Still had a rough bottom end.. but not an issue when on the go...

Bike was running very well indeed.

Best handling outing so far as i dropped forks from 19 to 15mm showing above top yoke. Stabilized the high speed running no end. The lack of weight was obvious pulling the front up out of tight bends and clearly having power to hit passed bikes down the straight. Enough to get moved up a group after first session to get some competition..

When i got home i checked bike over only to see the RR was showing signs of meltdown on one of the stator 3 yellow wires.. hmm. Caught just in time i hope before more mishap?

But more notable i saw one of the COPS had come loose a little..

I released the bottom boot on the COP and reconnected it to give a more positive connection. Might be the problem?

I thought maybe it is a tad too long and does not sit well enough, maybe only by a few mm, maybe the rubber boot pushes the good connection loose a touch?...As when i fired her up, the bottom end roughness was gone! Tick over fine....hmm...

After i find a fresh RR connector and rewire i will test some more...

How is yours functioning KGS? After fixing the loose coil has the stabling issue disappeared?

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I don't remember what COP's I'm using, but this is the number in their top surface. Denso 129700-4420-J0440. I do not have a volt meter on my VFR unfortunately, but will install one eventually. I have to go into work this afternoon, but have plans on tackling this tomorrow, and Friday, so I can get her to the local dealer for new tires, and fork seals. I have a bit to do to her to make her ridable, but 2 days in the garage should get it done!!!

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Maybe you mentioned it before douglas, but what coils are you using? Also, out of curiosity do you have a voltmeter on your bike? If so, would you be able to let us know what your readings are at idle before and after the mod? I'm still confused why certain aspects of this mod didn't work so well for me. And let us know how it goes!

A good ride on the weekend....

Still had a rough bottom end.. but not an issue when on the go...

Bike was running very well indeed.

Best handling outing so far as i dropped forks from 19 to 15mm showing above top yoke. Stabilized the high speed running no end. The lack of weight was obvious pulling the front up out of tight bends and clearly having power to hit passed bikes down the straight. Enough to get moved up a group after first session to get some competition..

When i got home i checked bike over only to see the RR was showing signs of meltdown on one of the stator 3 yellow wires.. hmm. Caught just in time i hope before more mishap?

But more notable i saw one of the COPS had come loose a little..

I released the bottom boot on the COP and reconnected it to give a more positive connection. Might be the problem?

I thought maybe it is a tad too long and does not sit well enough, maybe only by a few mm, maybe the rubber boot pushes the good connection loose a touch?...As when i fired her up, the bottom end roughness was gone! Tick over fine....hmm...

After i find a fresh RR connector and rewire i will test some more...

How is yours functioning KGS? After fixing the loose coil has the stabling issue disappeared?

Warm up sequence...You can listen while u read..

https://www.dropbox.com/s/w8qvt9din2nk8w9/clutch%20window%20test.AVI

8 mins in to this vid the steam clears and so i assume things are above 100C so bring revs up to 5000....

You tell me if they are firing ok?

When on track the revs sit at 8-10,000 as long as i dare...

The timing cover will be replaced soon. Was interesting too see what was happening behind there, but with a big bore kit looming i will want to get in there often.

I did hear cbr coils give a little different output reading so might be more suited than the gsxr ones i picked up?

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Nothing to add to the post just thanks for letting me hear the engine. I am having withdrawals. I must fire my motorcycle up tomorrow, tooooooooo loooooooong!!!!!!!!!!

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I believe that I have GSXR coils as well based off the part numbers from eBay, and the CBR coils. I really din't know how much difference it'll make if any, as this mod seems fairly untested, exceprt for a few people. I plan on making my own harness tomorrow, and I might buy some CBR coils just in case.

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KGS, after listening to the video a few times after the 7 min mark I am somewhat suspicious of you having a similar symptom to what I had. It is hard to tell from a online video clip but it seems as though after it warms up it starts to idle a little less even and when you rev it, unless I am hearing wrong, it seems to "clear it's throat" a touch as it revs higher. As in it doesn't just rev cleanly straight from idle towards higher RPM. Would you say it does this after it has warmed up past 80* C?

My bike worked great on the GSXR cop's for 700kms… then I started having the same issues I just described to you… however they got worse and worse. At about 800km's (I was on a 1000km ride) while stuck in traffic I had to rev the bike at at least 4000rpm to keep it running but once at 100km/h it would run decently enough… and even strong under higher throttle and higher rpm (though even this started to suffer closing in on the 1000km mark). A few times in town I had to pull over and let the bike cool below 75*C.

When I got home I could recreate the problem easily. Bike would run fine until it reached operating temperature then it would start to cough and misfire at low to mid rpm's. Switching to factory coils solved the problem immediately. So I ran the last 4000km with the stock coils. I have done some reorganizing and have found good spots to hide the factory coils… so that's what I'm going to use now.

I figured it's possible the coils I bought were just on their way out… although I find it strange I had 700km of the engine running great and then had two of the coils start acting up after the bike was warm.

I'm not trying to discourage anyone from doing the mod… just adding to the discussion. KGS do you think it's possible your bike has started stumbling after reaching operating temperatures?

I am wondering if the CBR coils might be a better option as they do have a different internal resistance… but I don't understand the science behind it.

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Not running them anymore… back to stock coils. They definitely weren't unseated. Did the same thing after uninstalling and reinstalling multiple times. Has your bike always had the "tick over hiccup" or is it more recent. And does it only start happening after the bike is up to operating temp?

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  • 5 months later...
  • Member Contributer

Just removed my k8 gsxr1000 cops.

The engine stall at 2000 seems to have gone. The pops have reduced..

Maybe i should have tried the honda cops?...

The plugs were very dirty and got a swift clean and rough re-gap... Poss not firing proper. leaving excess deposits on plug..

looks like engine runs better now... needs a good run out

but got put off my last track day due to rubber gone passed its wear markers, magnesium Dymags might want replacing ..

forks seals have leaked on one side.... were fine last track day, but that was the start of the season... lack of use?

With a big bore done and new wheels ill be looking at £5000.....

not much gonna happen any time soon...

Have seen fully kitted race Triumph triples for about 3500...

hmmmm

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  • 1 month later...
  • 1 month later...
  • Member Contributer

Going for a full service soon and might try the cops again..

Engine blueprint on the cards as i have rebuilt so many boat engines this year, my vfr rebuild should be fun, saving a fortune...

Spark still running poor (im down 1 pot) after putting genuine coils back on end of last year...

so....more updates be interesting from any1 else who has tried the stick coils.

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  • 4 months later...
  • Member Contributer

Has anyone tried running iridium plugs (in place of standard) with the COPs?

Seems most bikes using COPs also use iridium plugs, maybe there is a correlation?

My 5th gen with Iridium plugs are still working fine... I used 2008 CBR1K COPS... I know not 4th gen, but...

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Has anyone tried running iridium plugs (in place of standard) with the COPs?

Seems most bikes using COPs also use iridium plugs, maybe there is a correlation?

My 5th gen with Iridium plugs are still working fine... I used 2008 CBR1K COPS... I know not 4th gen, but...

+1, 2008 COP's with iridium plugs 5th gen, running great

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Thanks, but there is a separate thread for you 5th genners.

I'm using NGK Iridium plugs.

How many miles have you racked up? Any issues?

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  • 2 years later...
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 did a bunch of research online the other day and ordered a couple of stray COPs off eBay to look at.  I've now got a long one and a short one, one with an internal grommet and one with an external grommet.  (A 3440 and a 4800.)   I think the RC36 needs a short one, but I don't know yet until I test-fit.  I would want GSXR-style external grommets if possible, or adapt the OEM external grommets.

 

Untitled.jpg.d154bf812a0a5cb9b52fbd761607a2e2.jpg

 

All this was gleaned from the web, so all data is somewhat suspect... In particular I would ignore the Ohm readings, as they're susceptible to wide variation due to different testing apparatuses producing different values.  What does seem significant is this (note that some of these bikes use two coils, rather than four):

 

594acee81fc5b_HondaCoilData.jpg.10e81819b6e4c97c76ee9b3c59df0992.jpg

 

I'd guess that all of the Denso part numbers above actually have the same spec, but that could be wrong.  I could not find any official Denso specs, but the various Suzuki, Kawasaki, KTM and Honda manuals should list specs.

 

Am I right in thinking that an OEM 4-coil setup like the 3rd-4th gen would need to have 1.5 Ohm COPs wired in series? 

 

Ciao,

Edited by JZH
Updated the main table with more info
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Crickets!

 

Well, I'm not finished with the idea, yet.  I've completed the table a bit more (updated in the post above) and found someone on the web who had observed that if the only reason for wiring the COPs in series was to increase their resistance, the same result could be achieved by wiring in a 1 Ohm 20W resistor.  Would that really work?  I suppose it would--if wiring in series "works", that is...

 

I would like to know if the people who had already tried this on 3rd-4th gens had wired the COPs in series or in parallel.  Maybe I can piece it together from the thread?

 

Forgot to mention: I test -fit a 3440 and a 4800, which are a short, internal grommet, old style COP and a long, external grommet, old style COP, respectively.  The long is way too long.  The short looks to be a good fit for the RC36 front cylinders--once fully inserted it doesn't really protrude much more than the OEM plug boot and is not much bulkier (I didn't try it with the OEM fan).  The grommets don't do much sealing, however, even the external one.  A really thick o-ring would probably seal better--something like 4mm), but wouldn't really be an ideal solution. 

 

However, I did some more poking around the 'Web and discovered that the Yamaha R6 (1999-2002) used Mitsubishi F6T549-9630 COPs, which appear to be quite similar to the short Denso COPs (and the spec seems to be similar as well).  I've ordered some to test because they appear to have fairly large-diameter external grommets that might just be the right size to cover the RC36 plug opening... I live in hope!

 

Ciao,

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