CA's ExactFit coils. Anybody else have 'em?

[krista]

Man, that's really weird. I wish we were able to get hands on your bike. 

The primary resistance IS important, but the ohm value in and of itself is not a determining factor in their performance. What a lot of folks didn't say about the Dyna 3Ω coils we sold is that they taxed the charging system. Each coils was running 4A or more. What clued me in was when I would hear people talk about how an electrex regulator + the Dyna 3Ω would really make their bike wake up. I'm pretty sure the higher current of a 3Ω primary is pushing the limit on the carb'd Ducatis. That's why we switched to the black 5Ω model.

To keep the charging system safe, I originally spec'd these to be 4.6 ~ 5.0Ω. The secondary usually ends up 15kΩ or a little more, so 17~20kΩ is "normal". We have been checking primary resistance, but that was more of a pass/fail "0, good, ∞" test, not really a how close are they to 5Ω situation. This will get revisited and definitely be on my mind going forward.

How about a refund for these? And maybe we can find other 2000~2001 M900ie owners to try them (for free)? What really makes this odd is that slightly higher resistance shouldn't affect the output drivers in the 1.5 computer at all. The reason 0.3Ω and 0.5Ω and 1.0Ω primaries exist are so that the ignition driver can have a weaker drive on the output... a parallel is like USB vs RS232 serial communication on a computer. USB is lower voltage lower current TTL logic, while RS232 is higher voltage and more current.

Which spark plugs are you using?

[Howie]

Just for the hell of it try reducing the spark plug gap to the factory recommended .024-.028" gap.   

[koko64]

Well Shit.

First off though; huge thanks to Chris & Candice.  I had a pair of replacement coils in hand two days after speaking with Chris.

However, it would appear that my Monster is a high maintenance little pregnant dog.  There is clearly nothing wrong with the coils, as this new pair does the exact same thing.

Full disclosure:

Brand new DCPR8E's gapped at .036   
Brand new NGK 8515 plug wires w/ 5Ω resistor caps
Power & ground to each coil is correct (spade terminals are different sizes, just like OEM)
Full charge on battery
Full bag of gas
etc
etc
etc

I checked the new ones with a multimeter before installation; I didn't write down the values but it was real close to the first pair.

It ran like a striped-ass ape for about two blocks, then wouldn't idle.  I limped it back into the garage and shot this video immediately after dismount:

M900 Cough Cough Sputter Cough
I tossed the OEM coils back on, and went for a two hour ride with nary a hiccup.

Now what?

I'm running the black Dynas from Chris and my friend is running the new "Kelly" coils. Both are carbed Monsters (95 and 98) with FCR41s. These two bikes run the standard igniters. They both start and run beautifully. Another friend is running the green Dynas on a '92 Superlight with FCR 41s but his igniters died and he runs an Ignitech set up. All three bikes use the NGK DCPR8EIX iridium plugs and run strong.

If there is a compatibility issue with some FI bikes, Chris will sort it.

Lt Snyder's book (good book) mentions issues with running certain types of plug/ignition leads which he claims cause some electrical anomalies. The comment in his book was a little cryptic so I'm wondering if anyone had specific knowledge about the issue. Could this be a factor?

[Staggerlee]

Just for the hell of it try reducing the spark plug gap to the factory recommended .024-.028" gap.   

Ya know; I'd really like to say I tried that already, but I've had them on & off & back on again, I don't honestly remember.  I'll give it a shot.

Which spark plugs are you using?

DCPR8E's that I'm going to re-gap to factory spec.  Stay tuned. 

[Speeddog]

Perhaps you've got a bad spark plug wire or cap... I'm assuming that you didn't keep the same wires between new and old coils.

[Staggerlee]

Perhaps you've got a bad spark plug wire or cap... I'm assuming that you didn't keep the same wires between new and old coils.

I'm pretty sure I can rule that out. I've tried it with the wires & caps that are included in the kit, stock wires/caps & finally the NGK 8515 wires/caps and the issue is present in all configurations.

[Blue]

...And maybe we can find other 2000~2001 M900ie owners to try them (for free)?...

I have a 2000 M900ie with the stock coils/wires/caps and I would be willing to give these coils a try if you are looking for test bikes. 
The bike currently runs great as is!
The only caveat is the amount of snow on the ground so I could not take them for a test ride for another month.
Good luck with getting this resolved!

[krista]

Ya know; I'd really like to say I tried that already, but I've had them on & off & back on again, I don't honestly remember.  I'll give it a shot.

DCPR8E's that I'm going to re-gap to factory spec.  Stay tuned. 

Ah, ok. I was wondering because there is theory that non-resistor plugs (and wires) can cause RFI / EMI to the electrical system. In reality, it is a car stereo's audio circuits that are affected by this and I have yet to see anything point to EMI beyond that. Another far out there thing to try would be to get some cheap-o automotive supression-core wires. The last time I bought them, I got the cheapest 4 cylinder car "set" I could find and was under $10. I'm thinking/ assuming/ believing that they would screw into the coils the same way. In chasing down this rabbit hole, my goal would be to fully suppress any concept of EMI caused by the transmission lines...  Thanks again SO much for your patience! 

Perhaps you've got a bad spark plug wire or cap... I'm assuming that you didn't keep the same wires between new and old coils.

Yeah we went over that on the phone. I compliment Staggerlee's troubleshooting. He had already done everything I was asking him to do before we talked on the phone. Very thorough... he tried the wires and caps we supplied and then my wires, stock plug caps. Finally the NGK 8515, which I agree is a solid product without question.

I have a 2000 M900ie with the stock coils/wires/caps and I would be willing to give these coils a try if you are looking for test bikes. 
The bike currently runs great as is!
The only caveat is the amount of snow on the ground so I could not take them for a test ride for another month.
Good luck with getting this resolved!

Thank you sir!  Please email Candice and let her know. We'll all keep in touch. My preference is that the actual coils that were on Staggerlee's bike and misbehaving went on your bike to see if they repeat ... with the hope they straighten up and behave for your bike. Oh and snow? Wow, please keep warm and stay safe. It's kind of a good thing I keep too busy to watch news... the little bits I get are plenty scary.    Snow across the US, an already flooded Australia gets a CAT 5 hurricane?! Yuck... I grew up in Florida's hurricane alley, the panhandle area, and CAT 3 storms are no joke. I've had 4s but never seen a 5.

If there is a compatibility issue with some FI bikes, Chris will sort it.

Lt Snyder's book (good book) mentions issues with running certain types of plug/ignition leads which he claims cause some electrical anomalies. The comment in his book was a little cryptic so I'm wondering if anyone had specific knowledge about the issue. Could this be a factor?

Thanks for your vote of confidence and also for your positive input. IMHO, LT Snyder was basically reminding us all about the general industry assumption of EMI/RFI. Part of it, too, is that in the early 90s, there was a lot of snake-oil in the ignition arena. Like the splitfire plugs and Nology wires. Motorcycle Consumer News (under LT's stewardship at the time??) did controlled testing of various product and proved that when the rubber meets the road, the best setup is standard components with non-resistor plugs, which consistently added 1-2 hp.

The suck of it that ANY competent technician can set up a very believable test to prove any single product is BAD. Especially if marketing is the motivation. The difficulty is establishing that products are great and will stand the test of time. When I make stuff (or have stuff made for me), I always ask for the best of industry practices at every step of the way. If no compromises are made, there will be no questions or lingering doubt.

and my friend is running the new "Kelly" coils

  OMG, you got me on that one!

Thanks,
Chris

[Staggerlee]

Ah, ok. I was wondering because there is theory that non-resistor plugs (and wires) can cause RFI / EMI to the electrical system. In reality, it is a car stereo's audio circuits that are affected by this and I have yet to see anything point to EMI beyond that. Another far out there thing to try would be to get some cheap-o automotive supression-core wires. The last time I bought them, I got the cheapest 4 cylinder car "set" I could find and was under $10. I'm thinking/ assuming/ believing that they would screw into the coils the same way. In chasing down this rabbit hole, my goal would be to fully suppress any concept of EMI caused by the transmission lines...  Thanks again SO much for your patience! 

Yeah, that thought occurred to me as well.  But, the factory wires/caps are nothing special; certainly no better than the NGK 8515's why would this be an issue now?  Will a higher output coil generate more RFI than a resistor spark plug & cap can suppress?  I think I can pick up some bulk suppression core wire at my local speed shop; I'll give it a whirl.

Just for the hell of it try reducing the spark plug gap to the factory recommended .024-.028" gap.   

I re-gapped to .024 and there was an immediate improvement, but still not as solid of an idle as with the stock coils.  I opened them up a little further to .028 which had no effect.  I'm thinking about going even narrower than min spec just to see what happens.

[Howie]

Yeah, that thought occurred to me as well.  But, the factory wires/caps are nothing special; certainly no better than the NGK 8515's why would this be an issue now?  Will a higher output coil generate more RFI than a resistor spark plug & cap can suppress?  I think I can pick up some bulk suppression core wire at my local speed shop; I'll give it a whirl.

I re-gapped to .024 and there was an immediate improvement, but still not as solid of an idle as with the stock coils.  I opened them up a little further to .028 which had no effect.  I'm thinking about going even narrower than min spec just to see what happens.

No point in going smaller than .024.  Generally speaking, opening the gap helps the bike idle, gap too wide causes high speed misfire.  Stock gap is a compromise between the two.  Cheap suppression core wire is an interesting experiment, though 5K resistance should be more than enough.  Do keep in mind the wire will not be happy with the screw in connectors.

[Staggerlee]

No point in going smaller than .024.  Generally speaking, opening the gap helps the bike idle, gap too wide causes high speed misfire.  Stock gap is a compromise between the two.

Noted. 

Cheap suppression core wire is an interesting experiment, though 5K resistance should be more than enough.  Do keep in mind the wire will not be happy with the screw in connectors.

Yeah, I'm a little perplexed as to how I'm going to deal with that.  It looks like the aftermarket suppression core wires are meant to be used with the terminal lug installed on the plugs, which is easy enough.  Dunno how I can expect to get a solid connection at the coils.

[krista]

Yeah, I'm a little perplexed as to how I'm going to deal with that.  It looks like the aftermarket suppression core wires are meant to be used with the terminal lug installed on the plugs, which is easy enough.  Dunno how I can expect to get a solid connection at the coils.

I was looking at it ... it seems if you do the same thing as the stranded wire, the screw will bite into the middle of all that mess and get a good connection. I was thinking this while replacing the coil->distributor wire on my forklift... We had a left over wire from the old coil sets... so under the grotesque "hood" is this lone awesome red racing cable.

The theory behind suppressor core wires is pretty cool, too. It is considered fact that electrons flow on the surface of conductors... which is why fine stranded large cables can handle lots of current and not get too hot. Well the suppressor core wires are exceptionally thin wire spiral wound around the filament core.

Chris

[Staggerlee]

OK then.  I swung by the friendly O'Reilly's on the way home tonight and picked up a pair of generic 7mm
suppression core automotive replacement wires; OmniSpark is the brand.



I also threw in another fresh set of DCPR8E's at .024 and kept the terminal stud in place.  Trimmed off the long boot and screwed the wire into the coil; it's actually a very solid fit - almost feels more secure than the stranded core NGK's.

Initial results are positive; ran it around for an hour or so, no misfires at all.  This may have licked it.  Damn shame that my secksy new NGK wires are NFG, but I guess them's the breaks.  I'll run like this for a few days and post results.

[ducatiz]

OK then.  I swung by the friendly O'Reilly's on the way home tonight and picked up a pair of generic 7mm
suppression core automotive replacement wires; OmniSpark is the brand.

Do they have those wires in carbon fibre?? 

[Staggerlee]

Carbon Fibre "effect".  Same thing, right?