no start

[Grimly]

The resistive plug caps pre-dated electronic ignitions; not everthing was fitted with them, but the amount of disturbance to older radios was real.
It used to be quite an art, suppressing noise sources under the hood.
The story of it being to slightly elongate the spark is true, as far as it goes, but I don't think it makes all that much difference. Certainly, running an engine with no resistance on the plugs or leads hasn't lead me to believe there's any substantial advantage to it or not.
However, I believe that some electronic ignitions are built with the expectation of there being a resistance in place, which is why I now fit resistance plugs only and no resistance caps or leads.
Change plugs, get a new set of resistors in doing so. Much better than some ancient set of resistive caps or leads that were last changed who knows when.

 

[roeme]

What is this teaspoon trick? stainless or sliver? if silver will silver plate do in a pinch?

Teaspoon trick is dropping a teaspoon of fuel down the spark plug hole (and not more, lest you want to get a hydro lock).

Gets you a few combustions, sometimes even with the carbs off.

I have removed the resistor on caps as well and inserted brass rod in their place then used resistor plugs. The resistors can indeed go bad.

Can confirm; happened to me with my first GS, described in some other, ancient, thread

Would there be a disadvantage if no resistors in anything, wires, caps, nor plugs? Also do these resistors weaken the spark or slow it down? resistor could mean either. Why want a weaker spark & if slowed, seems that would be addressed with ign. timing?...I don'no.

As described by Grimly, it's mainly to prevent Radio interference. But that is/was mainly a problem with AM radio, old FM's...nowadays it's all digital anyway and these don't care much.

To my knowledge and experience, there's not much advantage nor disadvantage to run either with resistors or without; but as I said a year ago (sorry for thread necroing) with our vintage bikes it's beneficial not to run too many resistors and instead use just one - ideally the spark plug, because those in the caps go bad.

I can further confirm Grimly's description. The most benefit you'll get with that resistor business is to get rid of bad caps. The fuel doesn't really care how spiky, long nor wide your spark is (radios do), even with a lot of resistors it ignites well within an timing envelope that any difference would only be observable under lab conditions with the most sensitive equipment.

Certainly not at the dyno.

 

[Rob S.]

Just curious...what year? '80? '83?