Resistored COPS vs unresistored COPS

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I run my 2001 with stock TCI and Denso COPS. The iridium plugs I use are at .9mm which equals .0354

Bike runs great. BUT, my bike is also jetted perfect. No hickups at all. Any gear, any speed. I'm sure if I was rich or lean, I would not be able to run the larger gap.

I also go about 150 miles till the fuel light comes on.

BTW; I put in a Dyna 3000 years ago, when running stock coils. Swapped to COPS. Blew out the Dyna after a couple hundred miles. And I mean BLEW IT! The thing overheated the power transistors by pulling too much current being that their 1/2 the resistance of the stock coils (3 ohms vs 1.5 ohms for the COPS). The transistors burned a hole right through the Dyna's plastic case.
*Also, I was running Mitsubishi COPS back then.

After I went back to stock TCI, the bike ran fine for a couple of thousand miles, until I had an issue with just one of the COPS. The thing was sparking right through the case to the engine block. The bike would kind of 'miss' as low engine speeds. And when it was warm, it was almost a constant miss.
I had read where some Mitsubushi COPS were recalled for this, so, instead of just buying another Mitsu COP, I changed over to Densos. Got 'em on eBay from a GSXR as I remember.

All those issues were about 10, 000 miles ago. I haven't even changed plugs since then and all runs great with the stock TCI, Denso COPS, Iridium plugs, and 9mm (.0354) gap.

Vinnie
 
Yeah I never really understand why cops with standard TCI should be gapped at 26/27. I could understand if they were resistored which would lower current requiring a narrower gap but not with the non resistored ones which actually cause a higher current. To be honest I don't have enough knowledge to talk about how an increase in current in the primary would affect the secondary firing. My logic tells me that an increase in current would only allow for a quicker charge of the coil not affecting the discharge of the secondary. But I hope any electrical brainiac can correct me if I'm wrong.
 
Ok. My insight on this with the info I have is that the ignition unit will not affect it as its only the trigger for sparking, the performance of ignitech and stock digital TCI should be the same. Now to the coils themselves. I don't have the info available here now but assuming that the secondary in stock coil and cops is the same (which I'm almost sure it's not) an increase in current on the primary caused by a lower inner resistance will consequently raise current on the secondary thus making a stronger spark. How strong I don't know. But the current can be easily calculated and I'm sure there are equations around to relate current and plug gap. Main goal would be having the wider gap possible without misfire for a better burn and at the same time saving the plugs from electrolysis if gapped to narrow. Can someone post the stock coil and cops secondary resistance?
 

Latest posts

Back
Top