??? - spark plug wires - what are you folks doing?

Status
Not open for further replies.
The stock Champion plug caps arced like crazy in the rain. I threw them away (and I rarely do that). Replaced with Sparky type in the 70s.
Current setup here is: Champion N7YC plugs, NGK TB05EMD waterproof all black 5K plug caps, yellow cloth covered bumble bee stranded wires with clear sleeving under the tank to avoid abrasion. Ignition has a Rev-Tech dual tower coil and a new Tri-Spark which I still need to strobe time. (My wife was helping me by holding the throttle but some sort of insanity occurred and the bike revved sky high until I could reach up and turn off the key. Now she is afraid of it, so I'm waiting for another helper.)
 
Fast Eddie said:
That is really interesting LAB. Especially the finding that increased resistance leads to plugs failing to spark when ‘dirty’.

Indeed.
Fouled plugs are more inclined to fire if the HT voltage builds up in a shorter time.
Maybe excessive kohm values in the HT circuit make the voltage slower to build up, so the current leaks away through the dirty deposits, rather than jumping the plug gap.
 
'For you, Tommy, zer war is over.... Resistance is futile!'
Okay, poor attempt to get a corny one liner in, BUT....... Further to my earlier post, I so wanted to save face, put the new plug caps on (excellent service, GS!) and report no discernible difference in the real world...
So... It's a hot day today, which may affect performance, but perceived differences were: 'Stronger' (faster?) idle from starting, snicked it into first and it leapt forward and stalled.. doh!!! Okay, clutch adjust needed but never highlighted like that before. Usually, first half mile is constant adjusting of the choke lever to negate the odd misfire... not today! And choke discarded completely earlier than usual. Don't get me wrong, it wasn't a pig by any means, just the 'sweet spot' was constantly moving as the engine warmed up. Once warm I can't say there were quantum differences, if any at all, but so far it does seem that extra 5Kohm was affecting the end results... Plugs weren't cleaned at all, sole change was the plug caps.
(And NO buzzing in the headphones :) )
 
I’m rather new to the old bike scene, and, not knowing any better, when I recommissioned my 74 I simply used solid copper wire leads, along with NGK plugs, non-resistor. This then caused my ICM battery warning light thingy to play up, I was advised by the seller to use 5k ohm resistor plug caps. This cured it. I believe if I’d used resistor plugs then normal caps would have been needed. I also changed the cables as the first ones I purchased were a straight fitting into the coil and I’m not convinced that I was having misfiring issues as a consequence of them being so close to the rocker covers. I’ve changed the leads for a pair where they come out of the coil at a right angle, and a nice curve to the plug.
That's an interesting finding. I have a SparkBright Eclipse voltage warning LED and it has been "acting up". I am currently running non-suppressed plugs/wires/caps on a non-digital EI (Vape-Wassell). Wonder it this is a contributing factor. The maer of SparkBright thinks my issue is a poor connection on the LED's leads....I didn't know to tell him about my ignition setup...
 
Last edited:
That's an interesting finding. I have a SparkBright Eclipse voltage warning LED and it has been "acting up". I am currently running non-suppressed plugs/wires/caps on a non-digital EI (Vape-Wassell). Wonder it this is a contributing factor. The maer of SparkBright thinks my issue is a poor connection on the LED's leads....I didn't know to tell him about my ignition setup...
Well tried going back to 5k Ohm resistor plugs today, did not solve my Sparkbright issue, so looks like rewiring needed.
 
Status
Not open for further replies.
Back
Top