OEM Plug Cap Specs

[1948man]

Actually need just the resistance of a cap. On a cap removed from a plug wire, just measure from one end to the other. Actually on a whole set of caps if that's convenient.

[spadefoot]

Actually need just the resistance of a cap. On a cap removed from a plug wire, just measure from one end to the other. Actually on a whole set of caps if that's convenient.

I don't know if these numbers will be useful, but here you are (all in K-ohms):
1)9.3
2)10.14
3)65 !?!
4)14.4

Now, part of my reason for replacing my ignition was that I had a cylinder that wouldn't light reliably that changed when I moved the plug wire to the other cylinder. To be honest, until you asked me to test them, I didn't know you could take them off, so I didn't troubleshoot that far, but that 65K one may well explain my problems.

So the question is: What is it supposed to be? 10? The Dyna's I ordered are the 3ohm green ones, based on what I read in here, but I'm a little worried that these values were all WAY higher than 3.

[1948man]

Thanks, Spadefoot. Just wanted to see if there were any 5K ohm readings floating around on OEM caps. I realize they're old and possibly edging upward but it seems likely OEM caps weren't all 5K ohms.

[SqDancerLynn1]

If you took the resistor out and put a piece of metal in its place The bike would still run fine !!

[BassCliff]

Hi,

Here's some specs:

http://www.sudco.com/spark.html

The NGK plug caps come in 1K, 5K, and 10K ohm resistance values.

Depending on the manufacturing tolerance, resistors can vary 1%, 2%, 5%, 10%, etc.

Thank you for your indulgence,

BassCliff

[1948man]

Thanks for the link Cliff. Maybe Suzuki OEM also came in different resistances values also. If cap to cap secondary resistance measures within specs does it matter if that resistance is achieved with fairly high cap resistance and fairly low wire resistance. Or should there be specs for the wire and specs for the caps. I promise I won't obsess over this anymore after this question.

[BassCliff]

Hi,

See if this explains it...

http://www.magnecor.com/magnecor1/truth.htm

http://www.powerarc.com/sparkplug.htm

As I understand it, high resistance is necessary only for suppression to protect onboard electronic components from RFI and EFI noise or damage, to keep your radio from buzzing and your computer control circuits from frying. If you're using a 5K plug cap, there's no need for suppression (high resistance) wires on your motorcycle. And vice-versa; If you use suppression wire, use low resistance plug caps. A lot of resistance will cause smaller sparks.

Thank you for your indulgence,

BassCliff