Spark plug caps

[James England]

Hi everyone. I have a few questions about spark plug suppressor caps for the XS1100. My bike is fitted with the usual NGK black suppressor caps which have, I understand, a 5 ohm resistor built into them. From what I've read, this was done as a concession to people concerned about the plug sparks interfering with radio frequencies, rather than from any concern that the sparks would interfere with the TCI or other electronics on the bike (as they can do on modern vehicles). Am I correct?

I'd like to replace my plastic NGK plug caps with OEM replica ones made of metal. There are two types available, with or without 'noise suppression', so I'm assuming that means with or without a resistor. The ones without are half the price of the ones with and look much the same. So, is it possible to safely run the bike with metal caps without the resistor? I presume this means an increase in the power at the plug, since it's not being 'lost' at the resistor. If it is possible, is it likely to cause every radio and TV in my wake to do anything funny, or interfere with emergency radio frequencies etc?

[cywelchjr]

Hi everyone. I have a few questions about spark plug suppressor caps for the XS1100. My bike is fitted with the usual NGK black suppressor caps which have, I understand, a 5 ohm resistor built into them. From what I've read, this was done as a concession to people concerned about the plug sparks interfering with radio frequencies, rather than from any concern that the sparks would interfere with the TCI or other electronics on the bike (as they can do on modern vehicles). Am I correct?

I'd like to replace my plastic NGK plug caps with OEM replica ones made of metal. There are two types available, with or without 'noise suppression', so I'm assuming that means with or without a resistor. The ones without are half the price of the ones with and look much the same. So, is it possible to safely run the bike with metal caps without the resistor? I presume this means an increase in the power at the plug, since it's not being 'lost' at the resistor. If it is possible, is it likely to cause every radio and TV in my wake to do anything funny, or interfere with emergency radio frequencies etc?

Since you have the Iridium plugs, which as I understand come only is resistor type, you don't need the resistor caps as you only need either resistor plugs or resistor caps, not both at the same time (my understanding is it won't hurt to have both but they aren't needed). So you can get the ones without the resistor without issue with having the resistor plugs, which applies even to normal plugs as long as you get the R type resistor plugs.