SparkPlug Cap

[Gerrit]

I opened the Spakplug Cap, and noticed a tiny resitor within the cap.

What is the purpose of this resistor? Can they go faulty?

I assume it is there to prevent interference with nearby car radios? and to reduce the size of the spark so as not kill the sparkplug too soon

Perhaps this could be the reason for my intermittent misfire?

I have installed a standard sparkplug cap, and a new HT lead, and will see what it does on the way to work in the morning.

Gerrit

[benny hedges]

ah interesting.....
the storm standard plugs are (iirc) resistance plugs, as in the resistance is in the plug.
not sure if there should be a resistor in the plug cap?
maybe it's an aftermarket one?

you are right on the rf thing though, but tbh, who gives a sh1t lol, theres so much rf around these days anyway...

[Gerrit]

It seems to me this is the reall original spark plug cap, see the pic below.

Gerrit

http://www.cornerspeed.co.za/VTR/VTRsparkCap.jpg

[benny hedges]

mmmmh very odd...
wonder what happens if you remov the resistor then>>>
or if the joint corrodes and the resistance increases?
you mightve found something there bud...

[tony.mon]

it'll be a suppressor, to stop electrical interference on TV's etc.

[Gerrit]

Weird result. Went for a long ride on Saturday morning, with normal plug caps installed, no supressors.

Bike still had annoying misfire at high end, but what was strange, is that the rpm needle was jumping around like crazy, and the bike actually ran HOT, the needle went to the centre quite fast.

On Sat nite I reinstalled the plug caps that contain the resistors, went for a spin on Sunday, rpm needle smooth, bike did not run hot, still had the high-end misfire though.

Maybe Honda just had different spec bike bikes for different regions and as the climate down here is very warm, they probabaly calculated that the resistor would reduce the size of the spark sufficiently for the bike not to overheat?

I dunno, just guessing.

Gerrit

[Dysfunctional]

Hi,
I have no spark on my plugs. Coils are reading 16.7 ohms, but the actual caps are reading 1 (over range).

Any thoughts or is this normal?

I had the multimeter set on 200k for range

Cheers

[tony.mon]

It's simple to change the plug caps and eliminate them from the fault finding.

Or, if one is ok but the other doesn't spark, simply swap the coils front to back and see if the problem also transfers.

[Dysfunctional]

Thanks
Both coils seem to be ok. Do I have to get original caps for them or is there a substitute I could use do you know? Lead time on them for me is 3 weeks.